Ash Ketchum. EveryOne-Shot Character with a problem that he encounters gets his help. Unless in the case of older pretty girls, Brock beats him to it.
Diamond of Pokemon Special. Even when Team Galactic is not affiliated to them in any way, he still wants to stop their Evil Plan.
Goku from Dragon Ball. Every time someone, human or animal is in danger, be it genocide by evil alien overlord, a man trying to find water for his village, or a storm threatening to crush some dinosaur eggs, Goku has to help. This eventually rubs off on his son Gohan.
Dr. Tenma in Monster will not ignore any chance he sees to apply his medical skills for another's benefit, even though he's a fugitive on a manhunt. To the point where in the end he saves the life of the man he's been trying to kill for the entire series. This is the SECOND time he's saved his life, the first time being his first encounter with Johann and the reason he felt he had a duty to kill him.
Yuuri Shibuya of Kyo Kara Maoh not only goes all out to save random strangers, but also people who have outright tried to kill him!
Cowboy Bebop. Every episode, Spike and crew wander into some situation that really isn't their problem and has nothing to do with the main story, and yet they feel compelled to help. It's justified for Jet, what with him being a retired cop, but there's no excuse for Spike. They even get three new crew members this way.
Trigun's resident pacifist Vash the Stampede. To the point that when someone kills a spider to let the butterfly it was going to eat go free, he flips out at them: "I wanted to save them both!" Played for VERY dark laughs in later episodes as this former Crouching Moron, Hidden Badass with Improbable Aiming Skills gradually becomes incapable of saving anyone.
A Certain Magical Index's Touma Kamijo just can't contain his tendency to save people. Even if he just met them, he will go out of his way to help them even though he will gain nothing from it and will usually end up in the hospital. All of Touma's stories involve him saving someone in some way.
In a bit of Fridge Brilliance, after the first book/arc Touma loses his memory and the only thing he knows is that he saved this girl. Then in the next book/arc he has to save another girl and just figures that this was a common occurrence before he lost his memories.
To a lesser extent, Shiage Hamazura. Lampshaded by Birdway later in the series, as she points out that Hamazura may not want to help her out, but his nature means he's going to anyway.
Misaka Mikoto is also a sufferer of Chronic Heroine Syndrome. Deconstructed on a personal level— when it's her who really needs Chronic Heroes to solve her situation (such as during Sisters arc), she won't let anyone jump into it. A more mundane example is her friend Saten Ruiko, who is Chronic Muggle Heroine.
Ichigo Kurosaki in Bleach.He insists that all he wants is a normal life and he will only kill hollows that threaten his family, but he still manages to get involved in many, many problems. Whoops.
Late in the series after losing his powers Ichigo realized that regardless of what he might have said he had always wanted power to protect other people. It's the reason he chooses to regain his powers and give up the perfectly normal life he had claimed to want.
Allen Walker from D.Gray-Man. An All-Loving Hero that wishes to save everyone — humans and Akuma alike. If anyone is in danger while he's around, count on him to jump in and save them.
Deconstructed in Revolutionary Girl Utena, where Dios feels compelled to save everybody. This is taken to such an extreme extent that he utterly ruins his relationship with his younger sister by constantly neglecting her in favor of everyone who "needs him", and physically exhausting himself almost to the point of death.
Suzaku in Code Geass has this, due to his status as The Atoner. Lelouch also has elements of this where his friends (and especiallyhissister) are concerned. Euphemia could be considered an example of this trope as well.
Liar Game: Nao wants to save everyone else in the game by using her winnings to pay off their debts, no matter how cruel and deceptive they were towards her earlier.
InuYasha: Kagome has it bad, except instead of a compulsion to help people in danger, she has a compulsion to persuade Inu-Yasha to help people in danger. It always works.
Inuyasha doesn't always need Kagome to tell him to save people - he's saved everyone from two orphaned kids to his own romantic rival from whatever threat they were facing; in the first case the psychic demon he was fighting even commented on his heroic instinct. By the end of the series he's more distressed when he fails to save Kohaku and Kikyou than when he's forced to save someone.
Hayate the Combat Butler: It has been shown in at least one chapter that he has a compulsion to do anything for anyone who needs help. 1,000,000 yen for an apartment for two days? After paying off other people's loan sharks, broken vases (by a child who shouldn't have been carrying something like that anyways) and literally helping every single person he comes across with the money, he's stuck with nothing and considers sleeping on a bench. Hayate IS this trope.
Akane Tendō. While she has a Hair-Trigger Temper and is easy to anger, she's extremely kind and helpful towards anyone who needs help —whether they are her bitter enemies, random people on the street, or ill girls collapsed on the road. Once, while kidnapped by Pantyhose Tarō, she even dressed his ragged and bloody injury with a makeshift bandage as best as she could (in her own, clumsy way, but still...) to say nothing of the many times she stuck her neck out for Shampoo, Ukyō, and even Kodachi, none of whom ever returned the favor.
Ranma has this as well, even going so far as to help his enemies like Happōsai or Herb. He also has difficulty turning down requests from crying women. His many fiancées figure this out to manipulate him.
Digimon Xros Wars has Taiki Kudou, who tends to overexert himself while helping out random clubs. When the story starts, this compulsion has reached a point where his friend Akari follows him around with a bag full of energy drinks and a cushion for him to land on when he faints from exhaustion. Later on it's revealed that this compulsion stems from an incident in his childhood where he offered help to a boy who was sitting on the side of the street and cradling his head, but was rebuffed. After Taiki took that at face value, it turned out that the boy had been injured in a football game and had to be hospitalised for half a year. His catchphrase, "I just can't turn my back on him/her!" (or Hottokenai!) is based from this personality, and that even other people and Digimon (Wisemon and Nene) soon caught it.
Claus Valka from Last Exile is this trope due to Jumped at the Call. He feels morally inclined to become involved with the war based on his belief that it is the right thing to do. This means rescuing or otherwise helping just about everyone in his path ranging from his Unlucky Childhood Friend to his playfully sociopathic rival.
Fullmetal Alchemist: Winry, up to the point of saving an injured Scar's life, even when she knows he killed her parents.
Alphonse as well. After he watches just a few people die, he refuses to let anyone else be killed—even if they're enemies or total strangers.
Sailor Moon: Usagi Tsukino, the title character. In fact all the Sailor Senshi. After the Dark Kingdom arc when everyone but Usagi has been returned to their normal lives, all of them happen to be at the same location when a monster appears. Even though they don't have their powers, even though they don't even remember being Sailor Senshi, they all leap into the battle.
Bakemonogatari: Araragi Koyomi will do what ever it takes to help anyone, whether it be the aloof Sugar and Ice Personality he just met, the demon-possessed Yuri who also wants to kill him who has been stalking him or even the Vampire who also tried to kill him and currently lives off his blood.
Kuro Karatsu from The Kurosagi Corpse Delivery Service, at one point taking it so far as to sign up for a volunteer help program in Iraq during the second Gulf War so he can return a client (an illegal immigrant) to his family there (and for no pay, of course). Sasaki lampshades it almost immediately after meeting him.
Kotetsu T. Kaburagi/Wild Tiger from Tiger & Bunny takes his job as a superhero more seriously than any sane man ought to. Not only does he do borderline suicidal things to protect or save others (running into a burning building to save a single man while unpowered and unarmored, insisting on joining the Girls' Team in taking back Sternbild while still internally bleeding, Taking the Bullet for Barnaby etc.), but he preoccupied with it enough that his boss has to order him to use his vacation days so as not to violate the city's labor laws.
Nanatsu No Taizai: Elizabeth is the female version of this trope. Elizabeth will do anything to help innocent people, even if it could mean being arrested, beaten, or killed by it.
Naruto: Naruto Uzumaki. If there's a cause, Naruto will fight for it. The guy refuses to give up his quest to save Sasuke, despite Sasuke stating he wants to kill him, was willing to forgive the man who killed the closest person he had to a father figure, and — fortunately for the Shinobi Alliance, as it turns out — refuses to stay out of the war, despite being placed in hiding, because he can't bear the thought of his friends dying to protect him while he's hidden away in a safe place. Once on the battlefield, he sends clones to help every division, despite the risks it presents to his health, and has basically taken it upon himself to win the Fourth Ninja War. Itachi calls him on this, telling him he should rely more on his friends. The advice seems to go unheeded up until Neji's death.
This is treated as an actual character flaw in Medaka Box. While taking up the mantle of the All-Loving Hero was definitely an improvement over the borderline Empty Shell she was in her youth, Medaka's ability to form relationships without relying on the shounen convention of Defeat Means Friendship is practically non-existent. She literally has no identity outside that of The Heroine role.
Karasawa and the nameless Student Council Vice-President in Daily Lives of High School Boys both have this. When the student council's "odd jobs operation" had extended to student outside their school, Motoharu asked them to have a backbone and say "no"... in which they promptly said "no" to.
Quon of Towa No Quon. He has to save every single Attractor that he can, and is distraught whenever he fails to do so.
Yugo Hachiken of Silver Spoon. To the point he become "The guy who won't refuse you."
If he hears about a murder nearby, Shinichi Kudo always goes to solve the case. Even when he was on a date with Ran. Ran even lampshaded it.
"A murder has happened here. Now go to solve the case and come back, like you always do."
Muteki Kanban Musume: As a deconstruction of the Fighting Series, protagonist Miki Onimaru, poster girl for the Onimaru Ramen Shop, also deconstructs this trope: She always helps when she sees an injustice… often ruining the deliveries for her restaurant. It’s the best excuse for her to slack at her job.
Rock of Black Lagoon has gone out of his way to help characters multiple times. So far, many of them haven't ended well. Some examples:
He ends up making friends with Gretel while transporting her out of Roanapur, and is the only human being who has ever really treated her with dignity. Unfortunately, Gretel gets shot upon disembarking the boat.
He spares no effort to not only save Yukio from Chaka's grasp, but to also convince Balalaika to call off her war on the Yakuza clan Yukio took over. While he ends up convincing Balalaika, Yukio ends up dead anyway.
In the "Baile de la Muerte" arc, he comes up with a plan to save Roberta from herself. It works...but all he gets for a "thank you" is being shot by a blank, not to mention the verbal rebuff from Fabiola.
This is the defining character trait of Nanami from Kamisama Kiss. If somebody is in trouble and she is around she will make it her business to save that person.
Eita Touga of 12 Beast will not refuse anyone in need—regardless of their ability to compensate him and his army. It's a very good thing that most of his troops follow him out of honour or a sense of personal debt.
Madoka of Puella Magi Madoka Magica. While she isn't under contract she continually wants to become a Magical Girl despite knowing firsthand just how much it sucks to be one, something which causes Homura to finally crack her stoic front and no end to her grief. While she IS under contract in previous timelines she is always trying to encourage others to fight on,note Whether as a Magical Girl or as the concept of Hope not to mention her wish was to save a cat that got hit by a car. On top of that, as the Witch Kreimhild Gretchen her goal is to bring everyone into her care in order to end pain and suffering.
The Samaritan from Astro City, whose constant super-heroing leaves him with only a few hours of sleep every night and nearly no time to relax. Having a bio-organic computer that constantly monitors the news doesn't help.
Superman: It's what earned his "Big Blue Boy Scout" nickname. This facet of his personality is played with often, depending on what powers he has at the time. He always has "super hearing," but exactly how super tends to vary wildly; sometimes he can hear whispers from far across the city, and sometimes he can hear everything. Showing surprising depth, writers have included this into his character; if he can literally hear everything, then every panel of him doing something mundane means that we are seeing Superman make a deliberate decision to not help somebody, since there is always somebody who needs help somewhere and he has to hear them crying or screaming. Mention is often made that had to learn to "tune out" what he has to, since he has accepted that even he cannot be everywhere for everyone, and has to accept that some people need to be ignored.
It's taken to an extreme in Superman: Red Son, where at one point he has to leave a diplomatic reception to put out a fire at a chemical plant hundreds of miles away. When he becomes leader of the Soviet Union, his people eventually become either unwilling or incapable of taking care of themselves, since they know Superman will always show up to save them.
This leads him to Heroic BSOD in the Neil Gaiman one-shot comic "Green Lantern/Superman: Legend of the Green Flame" when he and Green Lantern (Hal Jordan) visit Hell and Superman's supersenses force him to hear and see everyone suffering there in excruciating detail. Almost as bad is his realization that they are in Self-Inflicted Hell and don't want his help.
This tendency almost got him killed the day before his wedding with Lois when he decided to stop a few crooks in an alley. Normally, this would be an incredibly easy feat for him, but at the time, he had completely lost his powers.
Spider-Man. Whenever he feels that something is not his problem, he remembers what his uncle Ben taught him: "With great power comes great responsibility".
This is often subverted, in that many times he'll bust his ass to get to the scene of a crime only to discover that one of New York's many many other superheroes already took care of it in the time it took him to get there.
Ultimate Spider-Man, in particular, feels the need to insert himself in any potentially hostile situation. While he generally does more good than harm, he also gets his butt kicked and makes a lot of things worse. Ultimate Team-Up shows what happens when he doesn't know what's going on very well.
The Flash also has this problem pretty badly. He is convinced that with his speed, it should be possible to be literally everywhere at once, and fix every problem he encounters. When a fire breaks out and cripples a woman in Keystone City, Flash is so disturbed by this that he goes to fellow speeder Johnny Quick to obtain Johnny's source of speed upgrade. The results are pretty predictable, and lessons are learned by all.
This is taken to its logical extreme in Kingdom Come, as the Flash quite literally becomes the speed force and as a result is EVERYWHERE in Keystone City. As a result of this, he's forever turned Keystone City into a crime free ghost town, and has lost his sense of self entirely, becoming not one Flash, but a strange mix between Jay Garrick, Barry Allen, and Wally West.
Depending on the story, most of the cast of Archie Comics could count. Betty Cooper got this once. Her nice girl/girl next door personality kept her exhausted with volunteer work and kinda turned her into a doormat.
Empowered, despite the fact that nearly everyone treats her like a joke. Any time she finds out about a problem, she will get involved, without fail, even if she knows she's in over her head.
Batman shows this too. Sometimes he may be an overly pragmatic jerkass or just accept that lives will be lost, other times he will NOT give up on saving everyone and everything, even at the cost of his own life. In Whatever Happened to The Caped Crusader?, two stories like this are told. In one, he passes a baby to Harvey Bullock and then is swept away by flood waters and drowns, and in another he throws a bomb and himself into Gotham River to explode so no one else is hurt.
This is a big part of why Bane's plan worked during Knight Fall. Even though he was sick (which Bane knew) he felt compelled to not get one minute of rest until he'd rounded up every single criminal Bane had busted out. At one point his body gave out on him and he collapsed on a random rooftop and getting him the only rest he'd get for that entire arc.
It also played a role in the follow up Knightsend when Batman's successor went crazy. Send Robin and Nightwing after him? Call in the Justice League? No. Clearly the only option is to physically rehabilitate after using surgery to recover from months of partial paralysis and retrain his body and skills with the help of one of his deadliest enemies, Shiva so that he could take down the new Batman himself.
Nightwing has this pretty bad, to the point where he's a lawful policeman by day and a vigilante by night. This obsession eventually costs him his relationship with Barbara Gordon. Then Blockbuster uses this against him, taunting him by saying he can kill everyone that Nightwing is close to. Even when his own life is threatened, Nightwing is concerned more with protecting the baddie than anything else.
In X-Men Noir, Thomas "The Angel" Halloway's entire life revolves around heroism — to the point that Professor Xavier diagnoses him with a completely new type of pathology, "heropathy". This is illustrated in their first encounter; Xavier asks Halloway why he cares about the X-Men. Halloway tells him that a woman, Jean Grey, is dead, the police aren't investigating her murder because she was with the X-Men... and he can't live in a world where a killer isn't brought to justice.
Patoruzu and Patoruzito are the most blatant Argentinian examples of this trope. The tagline of his comic book goes: "Courageous to the point of fearlessness. Altruist to the point of sacrifice. Brave to the point of heroism. But modest to the point of sainthood, and hilarious to the point of comedy."
Parodied in Twisted Toyfare Theatre, where Mego Spider-Man just wants to go home and watch TV, but he continually saves the day because he literally has no choice.
In fact it is because of this that things aren't as bad as they could be - Ichigo's helping hand has gathered an eclectic bunch of unlikely allies all who will follow him, nomatterwhat.
Blackjack of Project Horizons. Whenever she fails to save someone, she tends to take it very hard.
In the fan-manga of A Certain Magical IndexA Certain Bug Zapping Princess, Touma's Chronic Hero Syndrome is exaggeratedfor laughs. Touma will save any girl who needs help...even if it means abandoning the girl he was in the middle of saving.
Mary Jane Watson simply can't help herself from trying to fight supervillains and protect innocent bystanders as Spider-Woman. The problem with this is that Mary Jane pushes herself too hard as a Triple Shifter, and always ends up feeling extremely guilty whenever she feels like she's neglecting some of her responsibilities...even if it was because she was tied up dealing with something else. It's no wonder she eventually suffers a stress-induced Heroic BSOD when everything comes crashing down.
Sleepwalker is a subversion. Fighting evil and protecting the innocent is his race's whole reason for existing. His life would be completely meaningless if he couldn't do it.
In The Powers Of Harmony, this is a driving part of Pinkie Pie's characterization. The desire to help others is why she became Zecora's apprentice in the first place, and when she learns about the Healing ability granted to her by the Element of Laughter, she goes out of her way to put it to good use.
In Harry Potter and the Methods of Rationality, Neville accuses Harry of having this. He admits it, saying "Every time someone cries out in prayer and I can't answer, I feel guilty about not being God." He says it's a problem and he's working on it — but doesn't mention that by "working on it" he means "trying to become God".
Mr. Incredible from The Incredibles. The fact that he's forbidden by law from engaging in vigilante heroism is a major source of stress for him. His desire to go help a mugging victim eventually leads to a disastrous confrontation with his boss at Insuricare. In the DVD special features, the National Super Agency's file on Mr. Incredible lists this as one of his weaknesses. In the opening scene, as he rushes to his own wedding he has to stop to help in a police chase, then while on his way to do that he stops to help a woman get her cat out of a tree. Fortunately, said tree also came in VERY handy in stopping the car the criminals involved in said police chase were driving! His hero syndrome even shines through as an insurance worker. He is as helpful as possible to clients when company policy demands that he be as unhelpful as possible.
Films — Live-Action
This is the main source of dramatic tension in Watch On The Rhine—the hero, a member of La Résistance in Nazi-occupied Europe, has made it safely to America with his family. But when a leader of the anti-Nazi underground is reported to have been arrested, the hero feels duty-bound to go back and rescue him.
Mr. Nice Guy: The title character had absolutely nothing to do with the main plot until it stumbled across him.
George Bailey in Its A Wonderful Life systematically sacrificed every dream he had to help the people of Bedford Falls, and it ended up being all for naught when his uncle misplaced the money needed to keep George's business afloat. And if you think that's the end of the story you need to watch more movies.
The Fugitive: Richard Kimble gives himself away by ensuring a misdiagnosed boy gets the proper treatment when posing as a janitor at a hospital. He's not caught, although the sighting does tip off the US Marshals who are following him... and hints to them that he's a nice guy really.
Kick-Ass not only has this — watch the way he charges into a fight with three bigger, tougher guys to defend the guy they're beating up, despite having no training and no weapons besides a pair of sticks — but he manages to justify this by shaming the thugs, the gawking bystanders and the audience for not having Chronic Hero Syndrome.
Thug: What the fuck is wrong with you, man? You'd rather die for some piece of shit that you don't even fucking know? Kick-Ass: Three assholes laying into one guy while everyone else watches, and you wanna know what's wrong with me?! Yeah, I'd rather die! NOW BRING IT ON!
This is the fatal flaw of Daniel Rigg, the protagonist of Saw IV. In fact, his tests are designed explicitly to try and cure this. The first of them tells him to walk away from a woman in a trap, only for his attempting to save her anyway to, first, start the trap, then upon freeing her, she attempts to kill him because her instructions were that the police officer who tried to save her would put her in prison for the rest of her life. His ultimate test goes so far as to invertJust in Time, in that busting in at the last second Big Damn Heroes style was the absolute worst thing he could've done.
The Gone series. Brianna, or "Breeze". She spends most of her time rushing off to impress people with her powers and will, whenever trouble arises, blindly try to take out the threat herself - which nearly gets her killed several times. This is deconstructed during her POV chapters in Fear; the "stain" means she will not be able to use her powers, and she's afraid of being a disappointment to Sam if she doesn't kill Drake before that happens.
Lampshaded in the fifth book when Hermione points out that he has a "'saving people' thing" and that he could be walking into a trap. He's furious about that comment, pointing out that they didn't see an issue with that when he saved their lives before. Deconstructed when his hurry to save Sirius leads to the death he was trying to prevent.
"Neither of you understands Potter as I do. He does not need finding. Potter will come to me. I know his weakness, you see, his one great flaw. He will hate watching the others struck down around him, knowing that it is for him that it happens. He will want to stop it at any cost. He will come."
Also brought up during Goblet of Fire during the Second Task when Harry is charged with rescuing the person who is most important to them at the bottom of the school lake. Harry insists on trying to take back every hostage, even those that weren't his, misunderstanding that Dumbledore had taken every precaution necessary to ensure that no one gets hurt during the Triwizard Tournament. Harry gets high marks when it was decided that his insistence to save everyone was based on chivalry.
It's significant character development in Deathly Hallows when Harry knows exactly what Voldemort is up to and where he's going—and for once deliberately doesn't move to stop him, despite Voldemort gaining a valuable magical artifact in the process. (It works out for Harry in the end.) Also, Voldemort is right about Harry sacrificing himself, but he's not entirely correct about Harry's motivations. Harry has motives other than simple altruism: Harry himself has a fragment of Voldemort's soul within him, making Harry a de facto Horcrux. He is making the sacrifice to protect his friends, though—the same wayhis mother protectedhim.
In Grave Peril, Harry attends a Villain Party and is given a very interesting party favor, a gravestone and perpetually open plot. The inscription on the stone reads "He died doing the right thing."A few minutes later, he is given the choice between walking away and risking his life to save one innocent, which will also destabilize the vampire/wizard truce. The gravestone wasn't an insult, it was a hint. His response?
Bianca: "You would flirt with chaos, destruction—with war. For the sake of this one wounded soul?"
I smote my staff on the floor, reaching deep for power. Deeper than I've ever reached before. Outside, in the gathering morning, the air crackled with thunder.
Bianca, even Ortega looked abruptly uncertain, looking up and around, before focusing on me again.
"For the sake of one soul. For one loved one. For one life." I called power into my blasting rod, and its tip glowed incandescent white. "The way I see it, there's nothing else worth a war for."
In Turn Coat, Lara can tell he is sheltering Morgan because that's what Harry does: people in trouble come to him, and he helps them.
In the short story Warriors he attempts to bill an Archangel: even if he's working for Good, he's got to eat. He threatens to not come next time he hears the call. The Archangel immediately laughs at the implausibility of Harry turning away from those in need.
When we finally see his formative slugging match with He Who Walks Behind, we get this piece of solid gold:
No, it wasn't. But the world wasn't a fair place, was it? And I had more reason to know it than most people twice my age. The world wasn't nice, and it wasn't fair. People who didn't deserve it suffered and died every single day.
So what? So somebody ought to do something about it.
Deconstructed in Mercedes Lackey's world of Valdemar with the magical sword Needbefore she awakens to full sentience. Nasty things happen because the stupid bloody thing will NOT allow its wielder to let a woman come to harm, no matter what. Nasty for the wielder, because the sword has no concept of things like "impossible odds" (or "paying job"); occasionally nasty for the rescuees because it has no concept of "disproportionate response." And also that "no matter what" includes enemy women who have their own swords and are busily trying to hack Need's current wielder into pieces.
More normally, one of the qualities common to those Chosen to be Heralds is at least a little Chronic Hero Syndrome. They have Psychic Powers and normal people don't, so they have to use them to help those people, goes the thinking. Vanyel especially had it bad: as the most powerful Herald-Mage of his time, and eventually the only one left, no one else could protect The Kingdom the way he could.
Healers too, substituting Healing Hands for Psychic Powers. This version's only a real problem if a Healer comes across a plague or such beyond her resources, and attempts to fight it anyway rather than leave to get help.
From Predator things of the Century by Strugatski Brothers: "I'll get crazy for this. So many people — and I'm alone. I'm exactly like you, people — except I want to help You, and You don't help me..."
In particular, Thief of Time has Susan angrily call the protagonist "you... hero!" for going back to help his wounded mentor rather than saving the world; he at first takes it as a compliment until he recognises her tone. It should be remembered that Discworld heroes aren't exactly the brightest of people — many jokes are made throughout the series along those lines — so Susan, a teacher and great believer in common sense, won't think highly of them.
Indeed, most of the genuine "heroes" of Discworld, like Granny, Vimes, Susan and Moist are highly cynical and jaded people. More traditionally heroic characters are usually treated as fools (with the possible exception of Carrot, who manages to have it both ways). And then there's Rincewind....
In the Geronimo Stilton book, "The Mouse City Marathon," Geronimo is continually waylaid from running in the eponymous marathon because he keeps stopping to help people: getting a lost mousling back to his mom, stopping a purse-snatcher, even jumping off a bridge to rescue a fellow runner who fainted. Yet he still manages to come in first!
Keladry of Mindelan in Tamora Pierce's Protector of the Small quartet... she can't help but do exactly what the series name suggests, completely unable to turn down a cry for help from anyone smaller or weaker than herself (protecting animals as often as human beings) much to the exasperation of her friends and colleagues who feel obligated to help.
Wandering Djinn: The main character of the anthology seems unable to not try and save people.
Safehold: Merlin Athrawes of the series has a severe case of Chronic Hero Syndrome, which is subsequently lampshaded. Merlin himself notes that it tends to cause more problems than it solves. In particular, Merlin's actions have the potential to catastrophically effect his efforts to brig technology back to Safehold because the far above-average abilities he uses to enact his rescues can be interpreted by foes as demonic involvement.
The Knight in Rusty Armor at first is this, particularly about saving princesses and going to crusades (he does go to knight tournaments with as much enthusiasm, however). Rather than heroism, he does this to prove his courage and goodness to others.
In the Hand of Thrawn duology, Mara Jade accuses Luke Skywalker of occasionally suffering from this.
Mara Jade: You didn't think. You reacted, eager to save the world and to do it alone.
Later in the New Jedi Order series, she goes out of her way to explain to Anakin Solo how Luke (now her husband) hasn't exactly outgrown the mentality and even infused it into many of his students.
Don Quixote: Subverted and played for laughs; the protagonist is afflicted with this syndrome. The rest of the world reacts in the way we would expect them to in real life. The book not only lampshades this syndrome when Dorotea, (a beautiful woman impersonating a princess who really is trying to send Don Quixote home) but uses a temporary cure: the Damsel in Distress must simply ask The HeroThe Promise:
"Then what I ask," said the damsel, "is that your magnanimous person accompany me at once whither I will conduct you, and that you promise not to engage in any other adventure or quest until you have avenged me of a traitor who against all human and divine law, has usurped my kingdom."
The Stormlight Archive: Kaladin has a major case of this syndrome, he's always trying to save people and gets horribly depressed when he can't save/protect everyone, to the point of very nearly being Driven to Suicide several times.
In A Dance with Dragons from A Song of Ice and Fire Tyrion suggests that Danaerys has this. Consequently he recommends that Aegon, instead of showing up on her doorstep asking her to marry him, invade Westeros. He can't win, so she'll have to go to rescue him. This would not only put her own indefinitely delayed invasion plans back on track, but is also more likely to make a good first impression.
Jon Snow definitely has a case of this as well, especially after he is elected Lord Commander of the Night's Watch. He repeatedly goes out of his way trying to save everyone, no matter how unlikely the chances of it working are.
Knight Errant Michael Sevenson from the Knight and Rogue Series has a problem with this, and will on occasion put himself in harms way to help those who'd much rather see him in harms way.
It's more that he consciously tries to do this, because it's how a Knight errant should act. Several times per book he is shown demonstrating that he's naturally much more clever and subversive, but has to kick himself into it. This is the inverse of his sidekick, who tries to be a criminal and is good at it, but is constantly slipping and doing heroic things without thinking, and kicking himself for it afterward.
For all of Honor Harrington's debatable Mary Sue-ness, her major character flaw is her lack of self-assertiveness. She spends most of the series nigh-incapable of prioritizing her own needs over those of others, and it is used to the advantage of her political foes when they figure it out.
Derek Huntsman of the web-novel Domina is perfectly willing to risk his life to save a man he's known for less than an hour.
Witt in The Thin Red Line volunteers for each and every available mission, because he believes that his presence may may a difference for the better.
Since we've mentioned Merlin from Safehold and Honor Harrington from her own books, we might as well finish out the Weber trilogy with Bahzell of The War Gods. Everyone who meets the hradani pretty much instantly recognizes it. The entire series starts off when he can't ignore a servant being raped, even though he knows his intervention could mean war and tries to argue himself into why he should just walk away.
The Fugitive: Dr. Richard Kimble could probably have done a better job of hiding from the law if he hadn't constantly insinuated himself into strangers' problems. But of course he invariably saved the day, one way or another.
The same goes for David Banner in The Incredible Hulk, whose metamorphoses into the Hulk were both the reason he had to remain on the lam, and the only way he was able to save himself and those around him week after week.
Andromeda: Being an idealist from a more idealistic time dropped into a Craspack Universe, Dylan Hunt often suffers from this. Much to the annoyance of his more cynical/pragmatic crewmates.
Tyr Anasazi: I trust Dylan to be Dylan. When the universe collapses and dies, there will be three survivors: Tyr Anasazi, the cockroaches...and Dylan Hunt, trying to save the cockroaches.
Angel: The title character. Angel feels eternally guilty and constantly feels the need to save everyone. If he doesn't, he is burdened with guilt. Spike too, after season 5.
Being Human: Despite being a Cute Ghost Girloccasional ditz, Annie winds up saving people a number of times. She saves the humans that the vampires were using as a food supply, and saves Mitchell and George from their assailant at the end of the second season. She doesn't even care that whoever is in charge of the afterlife is angry at her for doing so, she wants to make sure her friends are safe. A slightly less impressive (but still valid) moment would be when she and George go to save Mitchell from the vampires, using a lot of screaming and flailing to take down one vampire.
Buffy the Vampire Slayer: The main heroine constantly suffers from this as well. Buffy is the Slayer so she feels responsible for everyone around her. Deaths particularly make her blame herself.
Community: Jeff. He lampshades it at one point, saying he "reluctantly accepts the mantle of leadership as no one else will". This despite Troy clearly being an adequate leader until this point, making Jeff's Chronic Hero Syndrome look thoroughly petty. Most of the time, Jeff is a thoroughly reluctant example of this trope; having spent most of his life being a self-involvedManipulative Bastard, his experiences at Greendale and the close friendships he's found himself making have resulted in him gradually becoming a Jerk with a Heart of Gold who ends up helping everyone around him despite himself.
The Doctor, the Doctor, dear GOD the Doctor. And boy does he suffer for it. Again and again and again, in every single reincarnation.
The TARDIS itself could also qualify, since it's an intelligent machine that always seems to plunk the Doctor down exactly when and where he's needed most, whether he wants to be there or not.
The Companions tend to have a touch of this as well. For example, Donna and the Doctor spend most of The Fires of Pompeii bickering about what to do about the fate of the people there — he insists that it's a fixed point in history, and they can't do anything to stop it. She feels that they should save at least one person. She finally convinces him to save a family of four.
When The Doctor thinks he's destined to die soon he decides to give up his heroism, devoting his last remaining days to himself, but he's really bad at it. When he realises people need help, he walks towards the TARDIS, repeatedly reminding himself it's not his problem, as soon as he reaches the door, he turns around and heads off to save the world. Realising that being a hero is what really made his life worthwhile.
Echo. Her desire to save the world, fight injustice and/or rescue the innocent is so deeply ingrained it survives repeated applications of Laser-Guided Amnesia.
Also, Agent Paul Ballard, combined with The Dulcinea Effect. Perhaps why they make such a good couple.
Early Edition: Gary, who has made it his mission to prevent every tragedy spelled out in the magic newspaper. He spends his time charting his day's activities for maximum efficiency, so that he can squeeze a coffee break between missions.
Malcolm Reynolds will steadfastly deny this to his grave, but deep down he suffers from a near-terminal example of this disease, to the point that it ended up with him on the opposite side of a psychotic crime lord and the Alliance's Operative.
In "Ariel" Simon, who until becoming a fugitive with his sister was a brilliant surgeon, goes to save a dying man while in the middle of the heist in a busy hospital, paying no mind to the risks of recognition and capture. He has a "save lives first, ask questions later" mentality that he also displays in "Bushwhacked" and "Safe". You can see him visibly suppressing it in the pilot when he refuses to treat Kaylee unless Mal runs. He would have helped that man regardless of whether River was screaming or not.
Peter Petrelli. Although this may simply be the writers constantly giving him the Idiot Ball. In Peter's defense, he does go out of his way to save the world. Or at least, Central Park, and sometimes very close friends. In Volume 5, he also hunts down Nathar/Sythan/Frankenstein's Monster and takes a nailgun to his hands and...other body parts to get his brother back.
Inversely, Nathan Petrelli (who happens to be Peter's politician big brother), who seems to love the phrase "it's somebody else's problem." God help the soul who tries to hurt his daughter, though.
When Wilson's second wife was showing House around a condo she said about Wilson, "He’s just so knight-in-shining armor, you know? Always there to support you, until he’s not, but by then you’re hooked." He stopped being there for her because he needed to be there for House.
And it works reciprocally as well: House is always there for Wilson, from when they met (at a medical convention when Wilson was a zombie from a failed marriage) to when Wilson, an oncologist, came down with an ultimately untreatable cancer, to the series finale, where House fakes his own death rather than go back to prison for six months when Wilson has only five months to live, effectively exchanging the rest of his life for the rest of Wilson's life.
JAG: Harmon Rabb, Jr. He even manages to acquit a defendant from a Decoy Trial in the episode "Defenseless".
Justified: God help the criminals that cross Raylan Givens' path. He's basically the only person keeping Harlan, KY from being a complete hellhole.
In Lois and Clark, this tendency almost breaks the eponymous couple apart in late season two. Clark keeps suddenly dropping out of conversation with Lois and disappearing at the worst possible moment because there is someone out there to be rescued. Naturally, Lois grows more understanding when she learns that Clark has a perfectly good reason for these disappearances (namely, being Superman).
LOST: Jack. This is a big plot point in the later seasons where Jack's "think first, ask questions later" brand of heroism eventually leads to many people being worse off than they were before they were "saved".
Was an Informed Attribute of Trapper. One of Hawkeye's letters home mentions him providing various forms of aid to the local people in exchange for (to them) small consideration (although a gallon a fresh milk was a nice thing to get). Being the sidekick, he didn't get it shown as much.
BJ had this as well, although he also had the problem of being the sidekick. He did get an entire episode dedicated to his heroic efforts to help a local family, who fled shelling at the end of the episode. Hawkeye comments at the end that they'll go back to camp, BJ will eat a lousy meal, have a bad night's sleep, and start looking for someone else to help tomorrow. BJ questions this, but Hawkeye affirms it, and BJ agrees he's right.
All Power Rangers get this the first time they morph and don't lose it until at least they stop being rangers, and perhaps longer. There's an awesome scene at the end of Power Rangers Lightspeed Rescue, where the villains are beaten once and for all and the team is preparing to go their separate ways... when a fire truck goes by. Our heroes look at each other, grin, and run after it, not even stopping to reclaim their morphers (their chief is behind them yelling "Hey, you forgot these!").
In Kaizoku Sentai Gokaiger, several of the former Rangers aren't letting their lack of powers stop them from doing what they can. One doesn't even let being dead stop him.
Primeval: Nick Cutter runs into a burning building to rescue his wife Helen. Not so unusual, but the building is on fire because she blew it up in an attempt to kill him and everyone else. He saves her after all that, and then she kills him.
Prison Break: Michael Scofield. It's explained by him having Low latent inhibition, combined with his genius IQ and his childhood being full of abandonment and abuse, he is unable to block out other people's suffering. This made him extremely empathetic and altruistic towards other people's emotions and he constantly puts others above himself. Interestingly, as the series has a rather dark setting, Michael often has to ignore it, which eats at his conscience. Furthermore, it's also shown to be a flaw of his, as he is downright obsessed with bringing down The Company, seemingly putting it above getting a normal life back, in contrast to the other characters.
Quantum Leap: Had this built into the premise: Dr. Sam Beckett couldn't proceed to his next Leap without putting right what once went wrong.
Revolution: Charlie Matheson has shown signs of this, like in "The Children's Crusade", when she wanted to save a young man named Peter from being taken away by the Monroe militia, and Miles Matheson had to remind her that they can't save everyone. Of course, Miles turns around later and helps in saving the young man and a lot of other children, so it undermines his point. Later on, Rachel Matheson and Aaron Pittman embark on a journey to the Tower. Aaron shows signs of this as well. It comes to head in "The Longest Day", where Rachel knocks out a man Aaron was trying to help and urges him to just leave him and continue on their journey. Her reasoning is unsympathetic (she's not trying to turn the power back on for the greater good, she just wants her son's death to be avenged), but she does have a point about being unable to save everyone.
Royal Pains: "No worries with Hank around. He has a hero complex." "It's not a complex. It's a neurosis."
Scrubs: Dr. Percival Ulysses Cox. Examples here, and here. In case the name didn't tip you off. At one point he tells J.D. that this is a slippery slope, because you start blaming yourself for deaths that aren't your fault. Later in the same episode, he succumbs to that very fate.
Sliders: Most plots in the first few seasons are driven by Quinn Mallory needlessly rushing to the aid of anyone in earshot, only to embroil himself and his friends into the troubles of whatever alternate reality they're in.
Smallville: Read Superman's description in the comics section, raise the AngstUp to Eleven, and you have his Smallville character. Chloe once asked Clark if he was afraid that if Lana learned self-defense then she wouldn't need a knight in shining armor to keep rescuing her from Smallville's dangers. He thinks he has to rescue her and everyone else too.
Inherited from the original film, Daniel Jackson was this which often put him at odds with the more pragmatic Jack O'Neill. Initially, Samantha Carter was given a feminist-oriented aspect of this which the writers quickly realised wasn't going to work for the show. As the series developed (and went down a drama to drama-with-comedy to comedy-with-drama route) the feminism angle was dropped from Sam, Daniel was given character development to give him a more pragmatic edge, and this trope became less relevant. At one point, however, it did essentially apply to the entire SG-1 team with different characters encouraging the team to "do the noble thing" in different episodes.
Similarly, this shows up to some extent in most of the main characters of Stargate Atlantis, depending on the situation. Sheppard definitely has it the worst, though.
Star Trek: Many Starfleet captains habitually encourage their crews or the alien of the week that it's sometimes okay to break a rule or two in order to do what's right.
The Vampire Diaries: Stefan Salvatore. He feels the constant need to try to save people and if he doesn't save them, he'll end up burdening guilt. Stefan might do this, not only because it's who he is as a person at his core, but possibly to atone for his dark past as a Ripper.
The West Wing: President Bartlet. Given his job as head of a country with 270 million inhabitants and major international responsibilities all over the globe, he is also chronically unable to fulfill his syndrome's needs. This often sends him into dark depressions, unable to get out until Leo or his wife tells him to stop being so egotistical as to think he can solve all the world's problems.
Mrs. Bartlet: Ah, yes. [He's gone to] pistol-whip the trucking industry... because he can't save a gunshot victim and he can't stop a hurricane.
"The Weight", by The Band, notably covered by many including Joan Osborne, is about this trope.
Majorly subverted in the Hatsune Miku song "Boss Death". She is a chronic hero, but only because she's lost all faith in humanity or the world itself.
Myths & Religion
Every single knight in the Arthurian myths seem to suffer this. "Questing" was all about going out and looking for trouble.
For example, at one point the knight Yvain has to be at a very specific location tomorrow in order to rescue a damsel, Lunete, from being burned at the stake. With plenty of time, he stays at a castle the night before, only to discover that the castle is being held to ransom by a giant; if no one can slay the giant, the next morning he will kill all the lord's remaining sons and have his minions rape the lord's daughter in front of everyone. Yvain tries to say "look, I do have this prior appointment and an innocent will die if I don't get there, so I'm afraid this isn't my problem"... but he turns back out of guilt, kills the giant, doesn't stay for congratulations, and runs off just in time to save Lunete... effectively pulling off two last minute Big Damn Heroes moments in a row.
In some versions of their myths, some Greek heroes are like this. It varies, though. Perseus comes out all right, and most of Heracles's moments of jerkiness are Hera invoked, but Theseus "has a way" with the daughters of the bandits he kills on the way to Athens, at one point kidnaps Helen when she was a young teen, tries to help a friend kidnap Persephone and also abandons or banishes a large number of other women. Odysseus is a little bit better, given that he is kept by women rather than forcing himself on them, but he is still a pirate (granted, that was normal for the time).
John Cena, in spades. Whether it's saving a Diva in distress, turning the tide of a three-or-four-or-10-against-one battle, or chasing bad guys off, John is your man. Probably the only reason he doesn't show up in every single segment to battle the villains and right the wrongs is that he gets too distracted chasing whatever bad guy caught his eye first.
One of the pitfalls of a high Compassion virtue in Exalted. Indeed, the rulebook's example of a circumstance that requires you to make a Virtue roll is a high-Compassion character falling victim to a mixture of this and Dudley Do-Right Stops to Help. Even worse, failing to satisfy this urge may drive up the character's Limit and trigger the Great Curse.
The Charity Virtue in the New World of Darkness encourages you to act like this in exchange for Willpower. The sample blurb for the virtue discusses a woman who's investigating a ritualistic Serial Killer... and who stops to pick up a hitchhiker with a broken arm (in real life, a favorite trick of Ted Bundy), even though she knows it could be a trap, because she fears he could end up a victim.
Some of the more Open-worldy sort of games allow the player to choose for themselves, either helping out every poor bastard who's dropped a ring in a sewer grate, ignoring everyone so you can get on with your business, or killing the asker for daring to ask for your aid.
Similarly, RPGs with large numbers of side quests irrelevant to the main plot can have the main character coming off as someone with Chronic Hero Syndrome.
Virtually every MMO steers the player's character into having Chronic Hero Syndrome. The character will often be sent out against a great evil... but on the way, they'll have to protect random people from threats, take shifts as a game warden, help gather materials for various building projects, and sometimes even be a relationship counselor, for everybody whose path they happen to cross.
Yuna of Final Fantasy X and Final Fantasy X-2, as lampshaded by Shinra after Yuna gets the Gullwings involved in yet another third party's request for help: "Hero. Summoner. Doormat." In fact, the other characters just love to lampshade this about Yuna, so much so that it pretty much becomes a Running Gag.
Tidus also qualifies. It is especially noticeable when the party hears about a monster eating chocobos. Tidus insists that they help defeat the monster but other members of the party point out that it isn't their problem.
Auron at one point tells Tidus that Jecht used to get his pilgrimage companions into all kinds of trouble when trying to help people because "it's the right thing to do". This includes trying to kill the Chocobo Eater.
Ramza from Final Fantasy Tactics is a Reconstruction. He's determined to help the common people, even as said people believe the propaganda that Ramza's a heretic and traitor. By contrast, his friend Delita is an Anti-Hero / Anti-Villain who backstabs his way to the top. Delita ends up king, Ramza ends up blown up and his companion gets executed for trying to tell the people Ramza saved the world. But the epilogue indicates that Ramza survived, shows Delita getting a severe Was It Really Worth It? moment, and the true story gets out four hundred years later.
Hawke of Dragon Age II gets drawn into other peoples' business just as frequently, though the results are more "mixed" than usual. The Sarcastic personality is particularly self-aware about this.
Commander Shepard in Mass Effect is also constantly being drawn in to other people's problems, and Paragon Shepard fulfills the trope by doing his or her best to help... although the player also has the opportunity, playing Shepard as a Renegade, to ignore them or make things worse.
Lampshaded in the second game, where you can pass by a couple you helped in the first game having a problem. One of them jokingly says, "Maybe we should ask random people off the street what they think."
A Lone Wanderer from Fallout 3 with positive karma likely suffers from this affliction, as he or she will never, no matter what, turn down an offer to help others. Of course, this being Fallout, seemingly nice things have a tendency to come and bite you in the ass, whether it's being hunted by bloodthirsty mercs, the whole "Tenpenny Tower" sidequest, or acertainunnamedMegatonsettler.
The Courier also suffers form this, however it ends up paying off as the factions who likes him/her ends up coming to his/her aid in the end game battle, also gives him/her lots of cool stuff.
Deconstructed by the Followers of the Apocalypse. They are truly noble, and do genuinely want to help people in the wasteland, but their own selflessness winds up screwing them over in almost every possible way in almost all of the endings, the only good ending they achieve is with the NCR.
The Player's character in the Fable series, in basically every quest you end up saving somebody from something, even more so in II with the DLCs, even when taking the routes to "Chaotic Evil" you still save the world, and a lot of random people along the way.
Adol from the Ys series. Even though Sealed Evil in a Can gets unsealed wherever he goes, he will always risk his neck to save the community he just came by. Adol is an interesting example since it's not entirely a coincidence that he ends up in places in need of saving: he went to Ys in the first place specifically because he heard it was under attack. Most people with Chronic Hero Syndrome end up helping the people around them because they can't help themselves, despite all the damage and disruption it causes their normal lives. Adol, by contrast, was told that there were still people in the world that were being eaten by dragons and enslaved by sorcerers at an impressionable age and decided then and there that somebody needed to do something about that.
Yuri Lowell from Tales of Vesperia is an odd version of this trope. It's both shown many times and stated many times that Yuri cannot ignore a innocent person in need. Of course, it's also been both stated and shown that he takes ita little too far. Not that those on the receiving end of Yuri's Justice didn't deserve it after what they did...
Flynn is also like this, though he prefers to use more diplomatic means of solving problems. Like Yuri, he sometimes takes things too far.
According to the first game, Sora from Kingdom Hearts is not supposed to meddle in the affairs of other worlds, except for fighting off Heartless. He pretty much completely ignores this fact, as he just cannot help helping people. By the second game, the whole "not supposed to meddle" thing is essentially forgotten, and Sora is even more of a chronic hero than ever. It's lampshaded by almost every single one of the game's more cynical characters.
Ōkami's Amaterasu is constantly getting distracted from her grand quest to save the world from the forces of evil because the cherry trees aren't blooming, a kid has lost his dog, and a girl wants to dig up something in Sasa Sanctuary's bamboo grove. All of these are necessary to advance the plot and Amaterasu herself. She's a goddess in mortal form, but she has been severely weakened over time. The accumulated praise she receives from helping people allows her to rebuild her power and enhance her abilities. Those seemingly small and insignificant acts of kindness and generosity are as integral to the saving the world as defeating Orochi.
Raymond Bryce from Disaster: Day of Crisis. The very objective of the game is to save as many people as possible. To quote Ray: "I still want to same them. Save you, save Lisa, save everyone".
Anyone in World of Warcraft with the Loremaster achievement. Requiring 2,843 quests to be completed ("only" 2,705 for Horde players), you're not only helping anyone who needs help with anything, you're hunting down every last person who might need so little as a mug of ale from a nearby brewery.
Guilty Gear: Ky Kiske. One of the reasons why the Post-War Administrative Bureau find him so easily manipulative is his overwhelming sense of justice that he feels the need to save everyone he can. Still, he's a very nice guy to have along as a friend. Just gullible. In the Drama CD, this one trait... got him killed.
Justified in Dragon Quest IX: the hero is a Celestrian whose primary role as a Guardian is to help mortals and collect the benevolessence they unknowingly exude afterwards. In short, having Chronic Hero Syndrome is a flapping job requirement.
Sety. In his own words, he simply cannot turn away when he sees someone in trouble, and boy does he get in problems due to it. And for better/worse, when Celice helps him whack the Distress Ball away in Chapter 8, he beats himself up due to not being able to rescue all the kids caught in the child hunts. "I'm no hero, sir. I'm a coward, if anything".
Hawk, being Sety's expy/replacement if Fury has no kids, suffers of exactly the same Fatal Flaw.
Red Dead Redemption's John Marston can be this if going for high honour. The game even keeps track of how many people you help. Everything from rescuing women and stopping thieves to stopping a carriage robbery in between trying to capture his former outlaw brethren. In fact, a late-game mission plays with this; during the Beecher's Hope ranching section of the game, while John is busy tending his new herd of cattle, a train races by under attack by outlaws, and John must choose whether or not to stay with the herd or intervene.
The Allied Nations in Red Alert 3: Paradox are sort of defined as a whole by their Chronic Hero Syndrome, but this causes serious problems because not everyone agrees with their definition of heroic action, which tends towards For Your Own Good on a national scale.
Although Word Of God asserts that he's an AFGNCAAP, the Marine has Chronic Hero Syndrome in both Doom II and The Plutonia Experiment. In the former, he volunteers to lead the strike force (consisting of only himself) to recapture Earth's spaceport and evacuate the planet's remaining citizens, and then he voluntarily dives back into Hell to reverse the invasion. In the latter, he cancels his hard-earned vacation just so he can be the point man to retake another captured spaceport.
The title character of NieR may be The Unfettered in his desire to keep Yonah safe, but that doesn't mean he won't stop to assist with such diverse problems as helping a merchant get started, a family get enough to eat, finding a lost dog, or getting a bartender rare supplies. Weiss snarks about it, but Nier says he can't afford to turn down any available odd job since it's what he and Yonah live on. Later, it's because it's what he's always done, and the occasional distraction keeps him sane - though one quest-giver opens up with (paraphrased) "Hey, you're that guy who'll do any job no matter how degrading, right?" It helps that Nier's usually not on a hard deadline for anything.
Star Ocean The Last Hope has Edge Maverick. Though his job is to find a new habitable planet suitable for humans, he quite quickly ends up trying to save a village of people he doesn't know, destroy a certain race to prevent them invading planets and then accidentally destroys a planet in a different dimension when he was only trying to help it, leading him to mentally break down and blame the entire thing on himself despite everything his friends try to say to him.
In Assassin's Creed: Revelations, Ezio's primary goal in Constantinople is to recover the keys that he needs to access the library at Masyaf, but along the way he keeps getting roped into the fight against injustice, and not unwillingly. As he needs help from the Assassins in the city, he winds up working to bolster them in their fight against the Templars. He also befriends Suleiman, the future Sultan, whose father and uncle are involved in a war for the succession of the Sultanate. Further, he meets and falls in love with a librarian in his search for the keys and is eventually forced to protect her from his enemies. At this point in his life he is bone-weary of the constant struggle, but as long as he remains an Assassin, he must keep fighting it.
In Resident Evil 6, Leon shows some hints of being this when he notices two men via security camera calling for help, before being overrun by zombies. He even attempts to go there to save the men, although Helena convinces him that it's already too late.
If Max Payne ever gains a whif of a serious crime or conspiracy, he sees it through to the end, consequences be damned. It's a plot point in Max Payne 2, as Vlad knows full well how Max would never just walk away, even when it's not something that directly involves him. In Max Payne 3 he even puts his life repeatedly on the line for a bunch of people that, most of which, he doesn't particularly even like that much.
The heroes of the Nasuverse tend to have this very, very badly.
Tsukihime: Tohno Shiki spends much of "Far Side" investigating the disappearance of Satsuki, who he barely knew.
And Mikiya in Kara no Kyoukai, who is in some ways a prototype version of Tohno Shiki.
Fate/stay night heavily deconstructs this with the protagonist Shirou Emiya. His need to try to save everyone is borne from a lack of a sense of self, wherein he can only find happiness as a result of other people's happiness. Many different characters comment on how messed up it is, and the Unlimited Blade Works route spends a majority of its time forcing Shirou to confront this in the form of his cynical Future Badass counterpart Archer, while the Heaven's Feel route is focused on him learning to overcome it.
Agatha claims to Othar Tryggvassen, Gentleman Adventurer! that she's uninterested in heroism. Immediately afterwards, she rushes out to defend the circus from an attacking Jägermonster. Clearly she won't be leading a normal life any time soon.
Gilgamesh Wulfenbach appears to be inflicted as well. While suffering from a gunshot and hallucinations, the only way to get him on his feet is to invoke the Damsel in Distress trope and make him think Zola needs her butt saved yet again.
Gil’s tendency to constantly save people is deconstructed several times, mostly with Agatha. He has problem understanding that someone may not want or need saving at all.
Supermegatopia's Weasel Boy series theorizes that heroism is "an instinct that makes people do good things before they can even begin to think about the consequences." Weasel Boy himself suffers from this in spades, even getting himself killed because he tries rescuing a little girl from a burning building just after being hit with a fast-acting poison.
Mr. Mighty from Everyday Heroes. On the first day with his new team, he helped a little old lady fix a flat tire, retrieved a truckload of chickens that were blocking traffic, saved a bus load of orphans from a speeding freight train, and foiled a bank robbery... all before he even got to the office. His biggest worry was being an hour late to work.
Todo from City of Reality suffers from this. It really interferes with his love life, as shown in this part of Chapter 6. Fortunately he manages to make it up to AV after she comes to accept that it's just how he is.
Elysia from Rumors of War exhibits symptoms of Chronic Hero Syndrome, going out of her way to help a young woman who's misplaced her lover. Of course, it's shown that her initial reluctance to help out meant she was unable to prevent a chain of events that culminated in the girl's disappearance, the torture of a (presumably) innocent (if somewhat creepy) man, and a violent confrontation with the girl's father.
Keychain of Creation, an Exalted webcomic, features in the character of Misho a person who perfectly embodies the benefits and drawbacks of a high Compassion Virtue. He cannot pass a scene of suffering and not offer to help, and while he's got more than enough power to do the job, it comes at the cost of possibly revealing himself as a Solar, which causes problems for the group thanks to the Wyld Hunt. The other problem with it is aptly demonstrated in thesestrips.
Rikk from Fans! has this in spades. It's surprising that the villains don't use it against him more often.
Freefall: Florence Ambrose has a case of this; it almost got her killed at one point, in a Shoot the Shaggy Dog incident at that. Of course, her grand objective is to prove that her species is too valuable to be allowed to go extinct, so it's probably a good thing, assuming she survives future heroism and doesn't get on the wrong side of the company that created her. (The company, Ecosystems Unlimited, is a Mega Corp. which would reach positively Shinra levels of villainousness if they could only find their rear with both hands, so this may be harder than it looks.)
John Egbert of Homestuck is totally unable to conceive of not throwing himself between other people and danger, no matter what the risk to himself is. Tellingly, upon gaining guaranteed immortality unless he dies in a just or heroic fashion, he immediately begins hatching heroic plans that relied upon abusing the immortality he would forfeit by carrying out heroic plans.
Atop the Fourth Wall: Lewis Lovhaug is seen to have this. Mostly because he is willing to defend anyone (examples include MarzGurl, Film Brain, and Iron Liz) leading to many heartwarming moments. It's kind of gotten to the point where someone being flamed/trolled and Linkara not showing up is odd!
Phase of the Whateley Universe. He was brought up in a filthy rich family where the motto is 'Goodkinds don't complain, they fix things'. And even though he has been kicked out of the family for turning into a mutant, he still tries to fix things for everyone around him. Even if some of them tell him to stop it.
Skitter in Worm. She tries to save people, even when it means going up against a gang leader who can literally turn into a dragon. She keeps this trait even after she becomes a supervillain. Scion spends all his time doing nothing but this, mostly because he's literally got nothing better to do and is following Kevin Norton's orders while trying to figure out his purpose. Eidolon also suffers from this, saying outright that "I live for this." In his case, though, the eventual realization that he may be (unconsciously) responsible for the creation of the Endbringers, which have killed hundreds of millions of humans over the last couple of decades hits him so hard he's left in a Heroic BSOD that he never recovers from.
Kim Possible practically defines this trope. She put up a website to bring in odd jobs like babysitting and got into fighting supervillains too. When asked why she doesn't turn down more requests, she replied "I'm not programmed that way."
South Park: Kyle Broflovski, but only when he's the protagonist to Cartman's antagonist (which happens quite a lot sometime after season five).
Samurai Jack: Jack who feels compelled to right wrongs at everywhere he goes. If he'd been able to kill Aku in episode one, then most of the wrongs he comes across would never have happened in the first place — this drives him.
Jack's Chronic Hero Syndrome is so pronounced that it frequently hampers his ultimate objective, to go back in time and prevent Aku's Dystopian future for ever occurring. The irony being that if Jack ever succeeded in his goal, the people he gives up his many opportunities to go into the past to help would in all likelihood never exist anymore.
Batman: The Animated Series: Used for laughs. The Dark Knight is burning rubber to make it across town to stop a mobster from demolishing an old building (with people inside) when he sees a city bus shoot past him, completely out of control. Batman can't leave them to die, but he reacts the same way one would if they had just hit a red light.
Batman: Perfect. Just perfect. (alters direction to save them)
Hey Arnold!: Arnold. His friends call him out on it and he decides to stop helping people. Then it turns out that, without his help, everyone's life goes to hell.
Katara, so very much. She even says once that she will "never, ever turn [her] back on people that need [her]". Thankfully, the other members of the group are better at recognizing that they can't always get distracted, and are more pragmatic.
Aang is kind of a mixed bag, since he ran away from home when he found out he was the Avatar and accidentally froze himself in an iceberg for 100 years. He continues heroism-avoidance at first, but once his Avatar superpowers start developing, he can hardly stop himself.
Dib from Invader Zim, who will constantly battle with Zim (and investigate any other paranormal threats that may present themselves) despite the fact that his classmates and family won't show any appreciation for it. One episode has him almost choose to let Zim subject his whole class to a horrible fate, even though he would suffer too; this is presented as the better option in some ways, though he decides against it in the end. It's hard to tell whether his primary motivation is love of humanity or hatred of Zim.
The protagonists of Street Sharks. One of the first things they do, after mutating into shark creatures, is save a woman from a car accident.
Finn from Adventure Time. He explains that he was abandoned as a baby and nobody stopped to help him, so he doesn't want anyone else to go through that.
Wild Kratts runs on this. Poor Martin and Chris just can't seem to catch a break.
Duke from G.I. Joe: Renegades, to such an extent that Scarlett not only starts to lampshade it, but eventually says its easier to just go along with him than try to argue.
Yugo of Wakfu can't bat an eye at a person in need without throwing his life on the line to help them. It's eventually lampshaded, mocked, and then outright discouraged by his companions, since he inevitably winds up making their quests over twice as long as they need to be, but he's too nice of a kid to back down.
It's not just him: Evangelyne once attempts to lead the group away from one such problem, since they are on an urgent quest, but finds herself unable to leave them to their fates.
While Ben Tennyson has been portrayed with different attitudes in his various series, this remains his most definite trait: Ben has a strong desire to help everyone in need, to the point it was the very first thing he thought about when getting the Omnitrix.
Homer Simpson is a very flawed person, but he is always willing to help his friends, close or not, if they are in trouble. In the movie, his selfishness overpowered his hero syndrome, but he ultimately did the right thing when he realized he was alienating his family by being selfish.
Grampa: Homer? What the hell are you doing now? Homer Simpson: Risking my life to save people I hate for reasons I don't quite understand. Gotta go!
In "Super Pink," The Pink Panther tries to be a superhero, but his attempts at aiding a little old lady—be it rescuing her cat from a tree to averting potential disaster—ends in disaster.
Ilana from Sym-Bionic Titan often has a compulsive need to help people in trouble, much to the frustration of Lance (and lesser so, Octus) as he believes protecting her comes first. The Shaman's Mind Rape takes advantage of this, causing her to believe that her planet's people need her and it's her fault that they're dying. She also feels this way towards the people of Earth, as the Mutraddi are there because they are searching for her.
The titular Wander of Wander Over Yonder feels the need to help out aliens he meets on all the planets he and Sylvia visit. This turns out to be his downfall in "The Fugitives" when he and Sylvia are wanted fugitives on a planet; she wants to escape, but her plans keep getting botched when he wanders off to help people. In "The Good Deed", all of his good deeds done to one person (or people) turn out to be the misfortune of others.
With a certain upbringing and basic medical knowledge anyone one can develop this syndrome.
Elliot Ness had a major case of this. In a famous example, while having dinner with his wife, he heard police sirens and jumped to his feet to join the chase. Since he now happened to have a nice selection of police with him, he decided to keep on going and lead them to bust a drug operation he knew of. His wife was simply left to wait at the restaurant.
It's a chronic condition amongst many firefighters, peace officers, and paramedics. They'll sometimes claim it's due to professional knowledge because they know how critical time is in an emergency and waiting for on-duty personnel to arrive might take too long. The reality is they can't help it because helping people is what they do. For a good deal of these professionals, this syndrome is the very reason they're in the jobs they chose, so it's kind of self-fulfilling.
In the case of police, this is a good thing for society in general (what more could we want from our police officers?) but can be horrific for the individual officers (those with this syndrome are likely to never recover from being forced to kill someone in the line of duty).
Certain personality types, such as ENFP's and the above mentioned characters do exist!