In the Sailor Moon anime, Sailor Moon actually offers the Big Bad of Sailor Moon S the MacGuffin she wanted all along to destroy the world because she refuses to sacrifice anyone. The show actually acknowledges how dangerous this gambit was when two of the Sailors, who were less than thrilled with the world coming so close to assured destruction, attacked her after the battles were over as a Secret Test of Character. In Sailor Stars, she does the same thing for that series' Big Bad, though by the time she actually has to confront her, it is after the Big Bad has killed her entire Sailor Team in combat. It actually works in her universe, but had it been slightly less on the idealistic side of the Sliding Scale of Idealism Versus Cynicism, she would have just pointlessly died and failed to save the world in the process.
Dragon Ball Z's Goku: The only Big Bad he didn't let live (Vegeta), offer to spare (Raditz, Capt. Ginyu, Frieza), or hope to be redeemed and fight again (Buu) was Cell — and even Cell got a free Senzu bean, which he makes up for by nearly letting Cell beat Gohan to death (despite having first hand knowledge that Gohan's Berserk Button was seeing his loved ones in danger, not his own peril).
It started really kicking in near the end of Dragon Ball proper, after he'd been trained by Kami. Perhaps some godly mercy permanently rubbed off on the Saiyan.
Vash from Trigun ventures into Stupid Good territory. He's absolutely iron-willed in his conviction to not ever kill ''anyone'', even if they're coming at him in droves with guns blazing. This gets him in extremely uncomfortable circumstances until he reaches his saturation point when caught in a Sadistic Choice, and pulls the trigger.
Vash could be argued as a sympathetic deconstruction of this. He suffers rather heavily to save people without hurting others to the point that when you see his bare chest, it is almost all either scar tissue or metal braces holding it together. He had plenty of opportunities to save many lives by ending a few, but always chose to resolve conflicts peacefully. Being forced to confront that choice when it concerned people that he knew personally was what finally broke him.
What's more, Vash is one of the few people on the planet who can live up to his ideal that he can save everyone due to his insane skills. He's aware that he is different in this respect, so its less him being stupidly good and more using his more then adequate gifts to protect everyone. Even at his lowest point, when faced with an enemy he simply can't defeat, mentioned above, he never gives up his ideals, but he does realize by the end that there are some forces he cannot overcome and he can't be everywhere at once, the last scene of the anime is him basically accepting this fact and moving on to try and live a more reasonable life.
Kinnikuman blunders into being Stupid Good a number of times. Some instances it's acceptable, like in the Throne arc when Kinnikuman Super Phoenix deliberately kills his subordinates who have become useless to him. Other times, like saying Warsman was the "better man" throughout their whole fight in spite of blatant cheating and nearly killing him, are not so acceptable.
Naruto. He insists in trying to save Sasuke and that Sasuke is his friend even when it's blatantly obvious that Sasuke does not want to be saved and considers Naruto just a nuisance, if that at all (not to mention the time he shoved a Chidori through Naruto's chest without knowledge that Naruto could regenerate). This in itself is bad enough, but the fact that Sasuke has done nothing but sprint down the slippery slope like a dog chasing a bone only makes Naruto's actions progressively worse.
Bleach: Orihime, oh Orihime... Your heart is always in the right place: you want to save your friends, those arrancar were hurt and one was even killed because of you, and you can't just sit back and let your friends get hurt for your sake. But honey, maybe you should use the brain that we know you have in there and think: your friends have already displayed their rescue fetishes, those arrancar were trying to kill you and one was still hitting you while you were healing her, and Aizen is a Magnificent Bastard who has probably planned for you to do all of that (and you know it, heck, you lampshaded it after he showed you the Hogyoku)! There's also the protagonist Ichigo, with his habit of sparing and even saving the enemies who try to kill him. As an example of how bad Ichigo can be with this, after waking up from his Hollow-side taking over, he saw that Ulquiorra, an already viciously powerful opponent had been dismembered by his outburst. His logical reaction was to offer that Ichigo could injure himself to an equal extent to have a fair fight with him.
The Ulquiorra incident is particularly bad because Ulquiorra demonstrates that he has the ability to regenerate limbs... Yeah it wasn't a smart time for him.
Yuuri from Kyou Kara Maou falls into this category. Even if the series is on the idealistic side, it doesn't change the fact that he forgives EVERYBODY (including traitors) and is willing to give the villains a second chance along with sparing him. It gives his friends a huge headache.
Suzaku from Code Geass has an instance of this, by offering to consider Ashford a neutral place for himself and his bitter rival, Kallen, even going so far as to not mention her illegal actions to his superiors. It doesn't go poorly, but he only barely avoids a violent confrontation.
His opinion of Britannia falls into this. He believes that the wrong means will not lead to anything good... despite the fact that Britannia conquered Japan with those means, and control the Japanese citizens through those means. He thinks that by joining them he could change it for the better. Yeah that turned out well.
The kirin of The Twelve Kingdoms are uniformly Stupid Good, but this is an accepted fact in-universe: as the kirin are supernatural creatures of mercy, it's something that is hardwired in their nature, and one of a ruler's most important challenges is learning when to ignore the advice of his kirin, since a kingdom cannot be ruled on compassion alone.
This applied to many superheroes in the Silver Age. When Superdickery wasn't in effect.
The Guardians of the Universe Green Lantern, although they are successful in creating the Green Lantern Corps, many of their other decision are the cause of most of their problems. Like the Man Hunters, or Sinestro, and tend to be to busy arguing with each other and their own Lanterns, that they take forever to decide on a proper solution.
"Successful" is relative here. Did they create the Green Lantern Corps? Yes. Did it fail to work out exactly as they hoped? Also yes. Did they create the Manhunters before that? Yes again. Do they have a looong tradition of creating the latest iteration of an ultimate peacekeeping force for the universe and having it get away from them in rather spectacular fashion? Er, well, not to put too fine a point on it, but yeah. Does their entire history point out to anyone a fraction of a percentage point how wise the Guardians claim to be that they're they pretty much their own worst enemies? Bingo.
In Leader of Men the Dementors were breeding out of control and in response, Hermione joined a group called the Peacekeepers which believed that they could be negotiated with. She soundly deplored Harry's resistance group's more successful tactics even though people were getting themselves Kissed in the attempt to destroy the soul-sucking little fiends. Even after they finally won, Hermione commented that it was pure genocide, which prompted Harry to snap that maybe she should've talked to the Dementors about not killing them.
Tirion Fordring in Frostblood straddles the line between Stupid Good and Lawful Stupid. Being a paladin, he abhors Jaina's decision to learn necromancy despite her reasonable explanation that she needs to learn about her new powers to control them. Worse yet is his readiness to execute Jaina for "killing a man on holy ground", ignoring that said man was a ghoul who was being destroyed just by being on holy ground and the vessel for Ner'zhul.
Harry Potter in To the Waters and the Wild. He was raised in the woods by rebel fairies and grew up learning how to talk to animals and trees and he just wants to befriend everyone he meets even trolls, giant spiders, and Dark Lords... though since Harry has learned faerie magic he is powerful enough to get away with it.
*I will eat you up! I will eat... I will rip.. Tear...* * Oh, are you hungry, then?* Harry reached out and petted the hard greenish scales gently. *That's not surprising, actually. It's got to be hard to find enough food when you are this size...* * I will eat you!* insisted the serpent. Harry had to laugh. *Oh, no, Mr. Basilisk, I'm not food. And neither is Tom, of course. But if you hang on a minute, I'll find you some sausages or something - the Slytherin boys always sneak some up to the common room with them after lunch. Ron always seems to get hungry in the late afternoon, and Crabbe and Goyle as well. Oh, but I do have an apple in my pocket.* Harry produced the apple and handed it to the poor snake. The apple looked ridiculously tiny compared to the vast green serpent.
Films — Live Action
In the movie Sunshine a spaceship is trying to reach the Sun (which is extinguishing) to detonate an uber-nuke into it (don't ask) and reactivate it. After a dramatic incident, it turns out there isn't enough oxygen for the crew to survive and complete the mission. The solution would be to kill one of them, who has gone insane — with his death they would spare enough oxygen to complete their task. The female protagonist, Cassie, takes the moral high ground and refuses to give her consent to the killing. Keep in mind that not only it was the sacrifice of one person versus the destruction of Earth and of the whole human race on it, but that they were all going to die anyway, since they had no chance to go back to Earth, whether they completed the mission or not.
Not always in the standard way, though. Sometimes, Forrest's efforts at actively opposing evil come off as this trope. For example, when he sees Jenny getting groped while playing folk music at a strip club, Forrest angrily attacks her tormentors - and Jenny herself tells him off for spoiling the performance.
Subverted in the movie Dogville - after being stupid good the entire movie, Nicole Kidman's character finally comes to the conclusion that arson is more fun than turning the other cheek.
Eddard Stark from A Song of Ice and Fire is bound by an inflexible code of honor. It isn't as irksome in the otherwise Crapsack World as one might expect. His flaw isn't his code of honor, but his belief that other people are better or more honest than they actually are and that they can be shamed into doing the right thing; he's willing to do the right thing, no matter how hard that may actually be.
His son, on the other hand, falls into this category towards the end.
Roose Bolton's legitimate son Domerick was an earnest and kind soul, who ended up being killed by his sadistic bastard brother Ramsay because he believed they could be best friends if they just got to know each other.
Carrot Ironfoundersson, Captain of the Ankh Morpork City Watch in Terry Pratchett's Discworld series, often appears to be this way; in fact, were he anyone else, he would be this way. But because he happens to be the lost One True King of Ankh, his natural innate charisma means people tend to behave toward him as he expects them to, whether they intended to or not.
In Twenty Years After, while on the run from the Queen (who wants to throw them in the Bastille), Athos learns that d'Artagnan and Porthos have already been captured. His response is to go to the Queen and ask her to release them, which — surprise, surprise — leads to him being imprisoned too. (And that's not even mentioning the times he stops his friends from killing the villain.)
The eighth book of the Sword of Truth series features a culture of people that are so Stupid Good that they won't even defend themselves when The Empire invades and starts with the evaile. When the Designated Hero shows up, some of them even serve as willing human shields for the Bad Guys, because war is bad, mmkay? Too Dumb to Live doesn't even begin to cover it.
Eve Forward's Villains by Necessity has the Balance Between Good and Evil central to its plot — if it's not maintained, the world will be sublimated into either a big light blur or a big dark blur with a possible domino effect for other worlds — but supports this mostly by populating the side of Good with Lawful StupidKnights Templar, with some Stupid Good lackeys for variety. This has the unfortunate effect of undermining the premise, since the "good" antagonists really aren't particularly good people, and the "evil" protagonists mostly aren't particularly evil either. Notably, one such Stupid Good lackey, the centaur bard Robin, eventually clues in and performs a Face-Heel Turn to side with the "evil" protagonists, and the Black Knight called Blackmail turns out to be a legendary paladin who has sided with the protagonists for the sake of saving the world and in disgust at his former True Companions's Lawful Stupid behavior.
In one of C. S. Forester's Horatio Hornblower novels, Hornblower can save his ship only by lying to a French officer that Napoleon has recently died. To make the enemy believe him, Hornblower has to support the lie by taking an oath on his honor as an officer. He plans to resign his commission in disgrace at the next port, because he has permanently dishonored himself. Fortunately for him, he finds out, by Jove, Napoleon really IS dead, so the lie was the truth all along. In Forester's defense, he conveys the standards of that culture so vividly that the reader can believe in Hornblower's scruples. This incident subverts the Stupid Good trope on a couple levels. Hornblower is arguably being "stupid good" in that he expects his enemies to completely ditch their plan solely because Hornblower gives his sworn word. However, he's not being "stupid" because they do take his word, and he's not being "good" because his actions are utterly shameful in his culture.
Sisterhood Series by Fern Michaels: Averted for the most part. Subverted, however, in Lethal Justice. Alexis Thorne a.k.a. Sara Whittier goes to see Arden Gillespie and Roland Sullivan after they have been caught embezzling and are soon to be arrested. She offers them some wine and tells them that she forgives them for framing her for their crimes and ruining her life. However, after Roland and Arden drink the wine, when asked why she's not drinking, Alexis reveals that she doctored the wine with tranquilizers and states that she's not stupid! Yep, she was just pretending to be Stupid Good just to get them to let their guards down! She follows it up by having a tattoo artist put "BASTARD" on Roland's forehead, "BITCH" on Arden's forehead, and tattoo Arden's body with snakes.
Star Wars Expanded Universe: To be honest, the New Republic and Luke Skywalker's Jedi Order have fallen victim to this. The trilogy that introduced Natasi "I Satan" Daala and Kyp Durron is particularly notable for this. Mon Mothma tried to negotiate peace between the New Republic and the Empire with Ambassador Furgen, who made it no secret that he was pure evil. In fact, he throws his drink in her face and says that there will never be peace between the two governments. Then it turned out later that the drink contained nanobots that were destroying her from the inside out! You would think Mon Mothma would have had more common sense by this point in time, but apparently not. Then there is the matter of Kyp Durron going around blowing up solar systems containing Imperial citizens with the Sun Crusher. Mon Mothma and her council know what he has done, but instead of punishing him, they hand him over to Luke Skywalker, who welcomes him back with open arms. Several characters were more than happy to point that this is not how life works, and Kyp now has the pleasure of Never Live It Down for the rest of his life!
Mon Mothma had been fighting the Empire for what, over a decade by then? More? Can you blame her for wanting peace? And for Kyp Durron...1.) He was under the influence of Exar Kun at the time. 2.) He became a great Jedi Master and would forever remain The Atoner. 3.) It was, at heart, a Jedi Problem.
The New Rebellion has a character named Femon reveal in her thoughts that she considers the New Republic too weak. She feels that the NR is too lenient with its enemies by practically never punishing them for their crimes. Femon is The Dragon to Big Bad Kueller/Dolph (think Adolf Hitler), who is Putting on the Reich, and she turns on him because she perceives that he has fallen to the same weakness as the NR, and he kills her for turning on him. On one side, this seems to say that everything she thinks is supposed to be dismissed and blown off. On the other side, this qualifies as Straw Man Has A Point, because the NR has done more reacting than acting.
Indeed, it is remarkable that the NR lasted for around 30 years living on this trope! At least the Yuuzhan Vong series did one thing right, and that was to tear this trope into tiny shreds!
The Wild Turkeys in The Book of the Dun Cow are friendly to a fault, but are too stupid to understand danger until it is too late. Because of this, they all die en masse.
The Valar in The Silmarillion. They're unable to comprehend that Morgoth is evil and especially that he is iredeemably, permanently evil, and believe him instantly when he claims to be reformed, only to have it blow up in their faces quite spectacularly later on.
Not really all the Valar (Varda, for example, caught on to Morgoth’s wickedness early on and never liked him, and Tulkas vocally opposed giving Morgoth a second chance) but specifically Manwë, whom it was said had a limited understanding of evil because he was so close to Eru, and the rest of the Valar sort of had to go along with his greater authority. It's also said that because they swore to let him out, they then had to do so.
On the one hand, their complete refusal to compromise even slightly on their principles would almost certainly have caused disaster for innocent people if Harry himself hadn't been more willing to be an Anti-Hero; in DeathMasks they threaten to kill a millennia-old sorcerer who is in a Willing ChannelerSymbiotic Possession with a Fallen Angel unless he gives them information that would save literally millions of people from a magic-powered plague. However, as soon as the man in question relinquishes the Artifact of Doom containing the angel, they immediately withdraw, despite it being clear to everyone (including them) that the man is evil even without the influence of the angel, and they would have left without the apocalypse-averting information rather than interfere in the man's (to all intents and purposes nonexistent) chance to seek redemption had Harry not beaten the information out of him.
On the other hand, they are prevented from falling firmly into this trope for two reasons; one, in the above example, Harry totally refutes the villain's assertions that they are too "weak" to do the pragmatic thing, since he is fully aware that it takes enormous personal strength to be so dedicated, and he greatly admires them for it even in the midst of his exasperation. Two, it is explicitly confirmed and proven that the knights have a Bargain with Heaven that works through Contrived Coincidence, and consequently nothing too terrible has ever come of them sticking to their principles, even if it takes something spectacularly improbable (or Harry's willingness to do the dirty work) to make things turn out mostly OK.
Pharoah Akhnaton in The Egyptian. He attempts to disband the army, confiscates the land of the priests of Ammon, causing them to curse it, distributes it to the poor without regard for whether or not they know how to farm and then when the Syrians revolt and the Hittites invade wants to bamkrupt what little of the treasury is left to buy them off despites being told by sevral sources that this will only convince them of Egypt's weakness and encourage their invasion.
Subverted by the Tinkers in The Wheel of Time. They're incredibly strict Actual Pacifists who never commit an act of violence no matter the provocation. Not in self-defense, not in defense of each other, not in defense of little helpless bunny rabbits. The thing is, they're not stupid: they're well aware that this means that they're going to spend a lot of time running away if they're lucky, and a lot of time dying if they're not, and they stick with it anyway because they prefer it to the alternative.
Live Action TV
In Red Dwarf episode "Demons and Angels", the characters meet their good and evil duplicates. Their "high" selves are so naive and trusting that they don't realise they are being deliberately shot, stabbed and crushed, and the High Kryten thinks a grenade is a "welcome gift".
Highlander: The Series has a guy who called himself Methos (not the real Methos played by Peter Wingfield) who wanted all Immortals to lay down their swords, embrace peace, and help little old ladies across the street at every opportunity. He didn't last through half the episode, getting decapitated by the Villain of the Week.
In Doctor Who, the Doctor can seem to veer wildly between Lawful Stupid and Stupid Good on occasion, particularly in the new series; he can ruthlessly dispatch and/or punish relatively minor foes or those who break his rules based on a belief in "no second chances" (such as leaving Adam stuck with a piece of futuristic technology in his head for attempting to profit from futuristic technology, or denying Britain a 'golden age' by manipulating the ousting of Harriet Jones from office after she ordered the destruction of a fleet of defeated alien invaders, something which went against the Doctor's efforts), whilst at the same time demonstrating an at-times almost boggling level of compassion and attempts at mercy towards foes whose sins have been much, much worse (such as attempting to forgive and/or rescue both the Master and Davros, each an Omnicidal Maniac with a raging God complex and an overall body-count well into the billions by this point). It's worth noting that those in the second group tend to be long-time recurring foes with Joker Immunity.
In the series Stargate SG-1, we have the Nox. At first, they seem to be this trope, causing the SG-1 team deep concern over the Go'auld's desire to take over their planet. As the team goes to leave, we find the Nox are pacifists who can make things invisible, revive the dead, yet prevent any fatal violence in either direction. Suffice it to say they are also Sufficiently Advanced Aliens who make the Go'auld appear to be cavemen. So they aren't exactly stupid, but they do fail to see the contradiction in how they look down on anyone who would resort to violence even in self-defense as primitive savages, while keeping to themselves the technology that allows their culture to protect itself nonviolently or undo the deaths caused by aggressors.
In the Star Trek TNG episode "Peak Performance", Jean-Luc Picard demonstrates this attitude when he disdains the idea of participating in a war simulation, because he believes that Starfleet's primary role should be diplomacy and exploration. (But Jean-Luc, what are all those torpedoes and phasers for?)
A visiting scientist regards Picard as showing this in "Silicon Avatar," when he says that he doesn't want to attack a crystalline entity responsible for the destruction of an entire colony (where the scientist's son was killed), but instead wants to try to communicate with it as a means to prevent further attacks. She thinks he's naive and kills the unique entity out of vengeance.
Subverted in the Star Trek TOS episode "Errand Of Mercy". The Organians appear to fit this trope for most of the episode, but it's eventually revealed that they were powerful Energy Beings and they were just humoring the Klingons when they let them take over their planet.
Double subverted with Edith Keeler from The City on the Edge of Forever. She knows who's a bad risk for her soup kitchen, but does not get that you cannot negotiate with a Hitler.
Subverted in the Adam WestBatman when Batman seems to let the gun moll for The Minstrel go simply because she said she was going to turn over a new leaf. Even Robin is aghast at how incredibly naive Batman (Even for this version) is for doing it, until Batman reveals that he placed a listening bug in her purse and let her go so she'd return to the villain's hide out.
Due South: Fraser often appears like this. Of course he is smarter than he looks.
Herschel in The Walking Deadwho is very protective of Walkers and keeps several of them in his barn. He regards them as just "sick people". Admittedly two of them were once family members but still.
He's cured of the Stupid part rather quickly.
Leslie Knope, Parks and Recreation, of course! A whole show based around the exploits of Stupid Good.
While alignment seems to not be an issue in the MMORPG Noob takes place in, Sparadrap slips naturally into that by several attempts to adopt monsters as pets, not taking factions into account when he randomly asks other players to join the guild, being friendly to hostile NPCs (notably asking them if they want to join the guild) and playing a healer class.
Sting's ridiculously trusting behavior earned him the Fan Nickname "The Dumbest Man In Pro Wrestling". Just count how many times he's been betrayed by Lex Luger... or look at the time he actually joined the Four Horsemen, not even suspecting that the whole thing might be a set-up to destroy him despite having spent the last two years feuding with their leader, Ric Flair. This seemed to change for a while when he adopted the Crow gimmick... and then he turned around and joined up with the Wolfpac the instant they split off from the nWo. Needless to say, they punked his ass out in a few months. Right through to his run in TNA over the last few years, Sting has virtually never had an ally who did not betray him. The most recent of his betrayals came after he made a Face-Heel Turn, joining up with the Main Event Mafia to teach the young wrestlers some respect. They eventually turfed him for not being evil and greedy enough, which, to his credit, he did admit he expected.
It's now been epically subverted with the advent of Immortal. Sting has pretty much gone from this trope to Dangerously Genre Savvy.
Usually it is more socially acceptable in pro wrestling for the WWE Divas to exhibit Stupid Good behavior - because, well, they're women, so they're "dizzy dames" who don't know any better. Special mention must go to Maria Kanellis, who was portrayed as extremely naive from day one, but who in the summer of 2009 made a judgment call that was pretty boneheaded even for her. Dolph Ziggler (formerly "Nicky" Nemeth of the Spirit Squad) was ruthlessly tearing his way up through the midcard (after himself starting out as a Stupid EvilNaďve Newcomer who tried to shake all his opponents' hands before their matches). It was apparent to anyone with half a brain that Ziggler was self-centered, arrogant, and prepared to do whatever it took to win the Intercontinental Championship. But Maria genuinely loved him, accompanied him to all his matches, and constantly made excuses for his behavior, even insisting that his bully shtick was just part of the kayfabe act and that away from the ring he was a completely decent person - in short, a Jerk with a Heart of Gold. She even became paranoid of other Divas who tried to warn her away from Ziggler, assuming that they were jealous of her. Maria's stubborn defense of Dolph eventually put her across the ring from his opponent for the Intercontinental Championship: Rey Mysterio, WWE's ultimate babyface. Fortunately, Maria took a brief hiatus from WWE and broke off her relationship with Dolph before he could totally corrupt her.
John Cena came off as this a bit during his mid 2011 feud with CM Punk. John was adamant that he defend his WWE title against Punk at the next PPV, despite Punk saying he was going to leave the company at midnight, just a little bit after said PPV. Yes, Vince McMahon seemed corrupt for trying to meddle in it and suspending Punk, running parallels to the Montreal Screwjob. John got his way....and Punk won, leaving the company with the title, exactly what Vince was trying to prevent.
Cena also won the 2012 Money in the Bank, giving him a title shot at any time of his choosing. Almost all previous winners have cashed in their opportunity on a weakened opponent, normally after they have been through a grueling match or have suffered a beat down, but Cena insisted on giving the champion fair warning because he wanted the fans to see a more exciting match. He won the match... but it was by disqualification, which means he was the first to cash in the Money in the Bank Contract and fail to win the title.
In Werewolf: The Apocalypse, members of the Children of Gaia tribe can be Stupid Good at times. The dichotomy of peace-loving werewolves is certainly interesting, but some of these hippies would sooner talk politics over tea with the creatures they're supposed to kill. The worst part is the tribebook for the Children of Gaia seems to encourage portraying them as the hippies of Werewolf-kind with no real pragmatism to counterbalance their idealism. On the other hand, the other Werewolf tribes tend to take Lawful Stupid to gory new heights. If they so much as think someone is tainted with the slightest bit of evil, GROWLSLASHKILLBITEMAIMKILLSLASH...
In Hunter The Reckoning, several groups of hunters seemed to fall exclusively into the realm of Lawful Stupid (Zeal) or Stupid Good (Mercy). This was meant to refer to the extremes in philosophy of the groups.
Anyone with a virtue rating higher than 7 becomes incurably insane and the Vision caste are, by design, meant to guide the others in looking at the bigger picture. So the issues with the Zeal and Mercy castes are more crippling overspecialization than anything. Furthermore, anyone who does anything has some horrible retribution waiting for them anyway.
The Innocent Creed (the ones who believe monsters can be people, too) had problems with this. Creed Book: Innocent had a viewpoint character who tried to help a vampire with her condition. After she ripped his legs off. As you can tell, White Wolf had problems with the "hippie" classes of the old line.
In the New World of Darkness, pretty much everyone with a Morality above 8 probably counts, considering you can ding a Morality 9 rating by simply refusing to do a good act when presented with the opportunity, and ding a Morality 10 rating by just thinking about doing something bad.
The Healer class in Healing is all you can do in a game where fighting is pretty much mandatory (you can only fight undead). Nothing prevents the rest of your party from indiscriminately slaughtering everything they see, though, making Healers more "conscientious objector/Combat Medic" than "Stupid Good/completely useless".
The Vow of Nonviolence from the Book of Exalted Deeds forbids attacking enemies... again, much like combat medics, who forfeit their special Geneva Convention protections against being knowingly fired upon if they carry combat arms or use their sidearms (which they are allowed to carry) as weapons of offense. The Vow of Peace requires that you work to stop other people doing violence even if they're on your side. This is both a purer form of the trope and unlikely to go down well with the rest of the party.
Book of Exalted Deeds also profiles several godlike celestial beings, including Queen Morwel and the Court of Stars, the Chaotic Good rulers of the eladrins. One of them, Gwynarwhyf, the Whirling Fury, is the patron of Good-aligned barbarians, but one legend about her claims she showed signs of this Trope andChaotic Stupid, claiming she tried to storm the Maw of Demogorgon and challenge the Prince of Demons (by herself). She was taken captive and survived only because Faerinaal (a more sensible member of the Court of Stars) was able to mount a successful rescue while Demogorgon's dual personality was in disagreement over the best way to torture her to death, and since then, Morwel has kept Gwynarwhyf "on a short leash". (As she says.)
The little-known Italian fantasy RPG Kata Kumbas has a playable class that is a Jesus-expy. In a game where experience is mostly gained by killing things, any player with this class forfeits ALL experience for the whole adventure if anything gets killed during the adventure itself. In other words, you lose all hope at gaining EXP if the other players kill even one of the Always Evil monsters you encounter. Thus, this trope will come into play a lot.
The closest thing Warhammer 40k has to a good (rather thannecessarily evil) faction are the Tau, who will make join-the-Greater-Good offers to other races and honestly expect them to say yes. In one particularly staggering example, one planet was under attack by Tyranids, when a Necron fleet showed and proceeded to vaporize everything. The Tau immediately sent a welcoming delegation (including an Ethereal) to the landing Necrons, who proceeded to vaporize everything.
Mayor Dobe of Fisherman's Horizon in Final Fantasy VIII is committed to pacifism and talking things out. When the town is attacked by a hostile army threatening to raze the entire place, he goes out alone to try to reason with the army's commanding officer - and when the officer physically attacks him and the heroes step in, he criticizes them for using violence.
Similarly, in Final Fantasy IX, the Cleyrans that lived in a big tree in the desert for hundreds of years without any fighting, thus they forgot how to defend themselves. When Brahne's forces invade to kill everyone in the tree in order to get a MacGuffin, the Clyerans try to reason with the soldiers as the soldiers are attacking! Unfortunately, unlike the above example, this gets them killed very quickly.
Valvatorez of Disgaea 4 also has a large streak of Stupid Good in him, as he is happily willing to put blind faith in people he knows to be duplicitous and untrustworthy in the name of the Power of Friendship.
Fate/stay night has Emiya Shiro, who takes his Stay in the Kitchen attitude towards his Servant Saber to the point of refusing to summon her in a battle where he would clearly die without her; only a Deus ex Machina saves his sorry hide. Though it can be inferred from this that Shirou's Stupid Good status is more properly a case of Always Save the Girl; he's trying to keep Saber from fighting in the hopes of keeping her from getting hurt. During the Unlimited Blade Works route, Rin comes to realize that his almost-suicidal altruism is largely the result of his survivor's guilt and attempting to justify surviving an accident that claimed the lives of many others.
Much like Shiro himself, Saber is also willing to sacrifice everything about herself for others. From the moment that she took up arms and became "king" of England, Saber spent her entire life fighting for others only to be betrayed near the end of her life. Her appearance in the Grail tournament was the result of her dying wish for her kingdom to prosper. Ironically enough, Shiro of all people is amazed at her selflessness, which only goes to further encourage his protective attitude towards her.
Daniel, Mordin Solus' assistant in Mass Effect 2 can be considered Stupid Good; if the player kills the thugs that were threatening Daniel's life, Daniel accuses the player of cold-blooded murder. Conversely, if the player lets the thugs go after they release Daniel, Daniel gets angry at Mordin, who says that he would have killed the thugs. Perhaps partially explained by Daniel being human; he likely swore the Hippocratic Oath while learning to be a doctor, and shooting people when you don't have to certainly qualifies as doing harm. Mordin, on the other hand, literally comes from a different world than Daniel, and the chances of its rules for physicians being exactly the same as those of Earth are quite slim.
A dossier conversation given by Lair of the Shadow Broker also shows that Daniel's Stupid Good tendencies actually make him a bad doctor. During the plague, he becomes far too emotional to actually focus on treating patients effectively. He is only an assistant, sure, but the first concern of a doctor during an epidemic sure as hell isn't going to be asking about the burial or death rituals of an already dead patient - it would be on quickly moving on to save the people who can be saved. Not to mention the Stupid Good-ness of leaving the clinic in the first place. The good intentions of getting the cure to the air control are undermined by a) high risk of death for an untrained medic and b) abandoning the many sick patients who need his medical help, even if the treatment he can offer is ineffective.
Fenthick in Neverwinter Nights, to the point that he gets himself hung for treason because he vouched for a deceptive but Obviously Evil lunatic that turned out to be spreading the very plague that he claimed to be trying to cure. Massively averted by the rest of the cast, though.
Pokémon Black and White gives us N, who leads Team Plasma on a crusade to "save" Pokémon from human enslavement, according to the ideals daddy taught him as he was growing up. He falls in this category because [A] Pokémon enjoy human company for the most part (though the abused probably wouldn't want to be around their tormentors for long, just like most anyone else) and [B] daddy happens to be Ghetsis, who intends to take over Unova once humanity is disarmed and is using all of Team Plasma, including his own son to achieve this end. The kid is to be pitied; the rest, not so much.
It didn't help that Ghetsis made sure to expose him exclusively to Pokemon that HAD been abused by Trainers.
From the Mega Man series, we have Mega Man himself. He refuses to believe Bass is an enemy, even as he's attacking. He knowingly walked into a trap to save Dr. Light, even after being told it was a fake, because it might be real. When learning that Dr. Wily has a cold, he takes him to the hospital insstead of bringing him to justice.
Mega Man 7 (the American version) attempts to avert the trope at the very end by having Mega Man attempting to kill Wily after being so fed up with all of the doctor's evil doings. While it makes logical sense to get rid of Dr. Wily, it also makes Mega Man look totally out of character, especially since he goes back to his good natured ways in the later sequels.
Dr. Light himself, despite not being the action hero, is also quite gullible and possibly just as stupid as Knuckles. A grand example of this is in Mega Man 10 where Dr. Wily begs Dr. Light and Mega Man to help him find a cure for the Roboenza virus after his own robots attacked him. Along with Mega Man, Dr. Light agrees to help Dr. Wily while ignoring the fact that Dr. Wily has ALWAYS gone back to his evil ways shortly after being released or broken out of prison.
Knuckles' main character trait from his debut in Sonic the Hedgehog 3 all the way to Sonic Adventure 2 (at least) was his extreme repeated gullibility concerning who the bad guy was.
The Pkunk from Star Control II edge into this territory at times, blithely accepting their fate of being wiped out by the Ilwrath and outright ignoring the danger of contacting their estranged Yehat kin because they're too busy being irritatingly benign space hippies.
Some World of Warcraft players feel this way about the current state of the Argent Crusade. In Wrath of the Lich King, they were the Only Sane Men who were pushing the fight towards the Lich King while the Horde and Alliance bickered. Come Cataclysm, they remain on good terms with both factions. It wouldn't be a problem if the Crusade hadn't specifically stated that they've re-focused their main goal as claiming Lordaeron for the living. This comes into conflict with the Forsaken, who are quickly turning into the Scourge 2.0 by killing the living to raise as new undead, all while plague-bombing and defiling a lot of the landscape. Tirion Fordring's apathy and unwillingness to act against them has been interpreted as either not wanting to provoke the Forsaken so he doesn't provoke the rest of the Horde - thus sacrificing his values for politics - or as him believing that the Forsaken deserve a chance - thus falling squarely into this trope.
Jaina Proudmoore often gets similar criticisms. In a recent short story, she was trying to talk to Varian to convince him to keep peace with the Horde. This took place after the novel that made it clear that Garrosh would stop at nothing to claim the entire planet for the Horde, and considering Thrall has so far done exactly nothing about that, one has to wonder what, exactly, she expects Varian to do.
However, this has been completely averted in Mists of Pandaria, where Garrosh decides to destroy Theramoore and kill most of its inhabitants in the process. Jaina finally breaks, and spectacularly so by going full-on the *other* way, questioning why the Horde should be allowed to exist and going on a Roaring Rampage of Revenge against Garrosh. The criticisms are now aimed at whether this character development is either believable or just too extreme.
Varian himself may had such a moment in the Siege of Orgrimmar, when he decided to give the Horde another chance under Vol'jin after disposing of Garrosh instead of taking advantage of their weakened state to defeat them once and for all. While such an outcome was inevitable (obviously a faction-based MMO can't have one of it's factions completely destroy or conquer the other) some, including a few of his fellow Alliance leaders, like Jaina, still question whether Varian truly had the interests of the Alliance at heart when he made this choice, or if he was just making a moral decision at the expense of his own faction. On the other hand, Wrathion alludes to how the rest of the Horde would not have gone down without a long and bloody fight, albeit one he sees as an acceptable sacrifice to unite all of Azeroth.
In the Fire Emblem game Radiant Dawn, the main character Micaiah epitomizes Stupid Good. She throws herself into hopeless battles in order to save random peasants; multiple times she spares the lives of mass murderers. Fortunately for her, the game is idealistic enough that it usually works out okay, and her victories in these missions make everyone look upon her as a savior.
Elincia, queen of Crimea from the same game, doesn't have it work out so well for her. She has proof Ludveck is rallying the rebellion to usurp her throne. Upon hearing that his army has mobilized, her first thought is diplomacy. Her hesitance to resort to violence allows her childhood friend to be captured and used as a bargaining chip for the throne of Crimea. She picks this moment to develop from stupid good to Badass Pacifist. She refuses to surrender the throne to an obvious tyrant, no matter the cost, even if that is her friend's life.
In Soraka's revised background in League of Legends, she's become this. Warwick tricks her into sacrificing her immortality to save him, so he can kill her and steal her heart. Soraka, an immortal being many years old whose own omnipotent guiding voice told her not to save him, believed the best of Warwick and didn't see through his ruse. Though she survived his elaborate trap, she must now live as a mortal without the voice of the stars guiding her.
In Tales of the Abyss, this is viciously deconstructed with Anise's parents Pamela and Oliver, whose Perpetual Poverty is caused by donating their entire salaries back to the Order of Lorelei and Oliver's tendency to fall for scams. Neither of them mind, because their faith protects them from harm, and if anyone's so desperate for money that they have to scam others, surely they deserve the charity, right? However, because of a scam Oliver fell for in the past, they're deeply in debt; Anise's precociousGold Digger behavior, Played for Laughs most of the time, takes on a rather less pleasant cast when it's understood that she's actually just trying to bail her parents out of their own idiocy. Later, we discover that it's even worse than that: Grand Maestro Mohs has been using their debt to practically enslave Anise and force her to act as The Mole for the sake of her parents.
It deconstructs this in the Jedi Knight storyline with Jedi Master Tol Braga, a Jedi Council member who, while not a pacifist, seems to believe any Sith can be redeemed. He justifies this belief based on an experience of his during the Great Offscreen War when he became locked in a duel with a member of the Dark Council, whom he dueled for more than a day. At the end of the fight, his opponent, who drew on strong emotions to fuel his power, was completely exhausted and drained of his hate and other powerful emotions, while Braga was still sustained by the Light Side. He then proceeded to redeem said Dark Council member, bringing him into the Jedi Order. However, this approach backfires spectacularly in the case of The Sith Emperor. During the conclusion of the second story act, an assault on the Emperor's secret fortress is planned, with the goal being to capture him and take him back to the Jedi Temple on Tython so that he may be redeemed, which would undermine the very fabric of Sith society were it to succeed. However, Braga fails to realize that the Empreror is much closer to an Eldritch Abomination than "just another Sith" as he claims before the mission. This results in every member of the strike team being overpowered easily by the Emperor and being mind-controlled into doing his bidding. The player escapes what is implied to be a few months later with the help of their The Obi-Wan, the spirit of their deceased master Orgus Din. This results in them confronting the corrupted strike team members and freeing them one by one during the third act, all the while foiling the Emperor's galaxy- annihilating plans, until a final confrontation with Tol Braga himself. During this confrontation, it is revealed that Braga did not need to be mind manipulated by the Emperor into falling to the Dark Side, instead, being faced with complete and utter failure to redeem him, sunk into despair and decided the galaxy was not worth trying to protect.
The player can play this trope straight themslves in the conclusion of the Jedi Knight storyline depending on their decisions, though it fails, as well as some of the other storylines.
Grace of El Goonish Shive. Despite being a Tykebomb, raised in a laboratory by unethical scientists, and then later by a ruthless, murderous mutant, she's a complete pacifist, and can't stomach ANY kind of violence. In the end, facing down Damien — a mutant supremacist who intends to annihilate all of humanity, used to savagely beat her while she was a child, intends to rape and forcibly impregnate her to create a race of superhumans, killed her father and then showed her his severed head when she was five, and is now about to kill all her friends — she FINALLY snaps and goes Crouching Moron, Hidden Badass on his ass. Halfway through tearing him a new one, however, she regains her self-control, apologizes for attacking him, asks him to surrender (pretty please with sugar on top?) and refuses to attack him further. The only reason he still managed to wind up dead is that he attempted a Taking You with Me gambit, only to have Grace saved by a Deus ex Machina. And afterwards, Grace is traumatized for DAYS about having acted violently.
Lampshaded somewhat later, when history-class introduces Grace to World War II, Nazis, Hitler, and concentration-camps. Making her realize that Damien was basically a second Hitler (with superpowers), and that offering him a chance to surrender and walk away was probably really stupid.
Those incidents apparently left their mark, since she's thrown this characterization off entirely. Perceived threats to her friends have become an official Berserk Button, and while she admits that she'd still prefer nonviolent solutions, in worst-case scenarios she's perfectly willing to use lethal force.
Helix, the robot from Freefall definitely qualifies as Stupid Good, but it sometimes works out as it causes him to derail Sam's more Chaotic Stupid schemes. (In fairness, most if not all of the robots in the comic come across as a bit naive at times, Helix just perhaps a bit more so than most. Justified in that their individual neural networks are still evolving and a lot of things simply are intellectual new ground for many of them as of yet.)
Although the page image up top here is of Piffany from Nodwick, she isn't this trope. While she is The Pollyanna, she is also just so Badass Adorable that she can get away with it. Or perhaps she is this trope, but she has such a "reality distortion field" around her that evil creatures in her presence can be forced to behave if they are told she would cry if they didn't.
She did, at one point, hire a Stupid Good paladin for the party to serve as a role model for Yeagar. Who insisted on challenging every Undead Mook they found so they couldn't harm the population, instead of making a beeline for the leader, getting Nodwick killed even more than usual. Even Piffany herself realized he was Too Dumb to Live.
On the other hand, Celia's reaction to the unnecessary killing of goblins could be interpreted as being the Only Sane Man; she reacts like a real person to real deaths, not like an RPG character. Her inability to recognise that Greysky City is completely evil is another matter, though...
Celia's Stupid Good tendencies were subverted in this strip with her rather ruthless reason for not wanting to abandon Belkar.
Then there's Elan. The adventure game even lists his alignment as "Foolish Good". That said, most of his actions that really fit this trope are based on willful ignorance and his belief in following narrative conventions about how heroes are supposed to act rather than his very real stupidity or an inability to understand why it might not be a good idea.
Pretty much everyone in the "Dimension of Lame" from Sluggy Freelance is Stupid Good — so pacifistic that one mage attempted to heal a demon that was attacking her friends, and that they can be convinced that throwing food at the demons is as bad as the demons eating people alive. Torg ends up describing them as "not as good as they think they are."
Rusty and Co.'s Madeline is truly a ditzydo-gooder — who is absolutely Badass. However, she has her Stupid Good moments, as when she condoled with a monster that was, indeed, complaining of its trouble but, on the other hand, still had a chokehold on one of her companions.
Elisa from Dead Space Downfall, who was more worried about saving the crew than quarantining the ship. She also stopped Dr. Kyne from destroying the ship because there are about 10 other people still alive (and they all die, anyway).
Family Guylampshaded this in "Brian Goes Back to College." Brian is given the chance to cheat on an exam but chooses not to, and fails the class. He then tries to use the old "At least I failed honorably" and "At least I didn't quit" cliches. The entire family immediately calls bullshit on this, saying that he should've just cheated and passed. The whole point of taking that physics class was to get a college degree that would allow him to be hired for a dream writing job he was otherwise completely qualified for.
True, it is morally preferable that he be honest, but it is rather pious of him to swagger like that about failing a class for a degree that was going to be purely superficial.
Lisa Simpson, in an uncharacteristic moment of stupidity, tears up a cheque for $12 million from Mr Burns because it's "the right thing to do". It's not even like an unbanked cheque IS money; it's just potential money and Lisa should know that. Far better would have been to accept the money and donate it to eco-based charities to try to make up, and she could even make the donation anonymously to avoid taking credit, but oh no, she's too pure even for that. It's not a Crowning Moment of Heartwarming, but rather sickening in its piousness.
And after she gives up the potential money, Homer has a heart attack and has to go to the hospital. He understands why Lisa did it, but he's under the impression the amount was much smaller than it was. Lisa corrects him. Cue "Code Blue, Code Blue!"
It's not the last time. During the Spellympics she is offered a scholarship to any of the Seven Sisters colleges to throw the tournament (And a hot plate!). Obviously this is a moral dilemma, so she asks Marge if the family can afford to send her to college. Marge admits that it would be very hard on the family. Regardless, Lisa decides it's the 'right' thing to win anyway, even though her real reason for competing was for popularity and attention. As with the Family Guy example, it's better that she's honest, but she could have decided to spell to the end honestly and see what came of it without risking the scholarship, or she could have outed the rigged contest to officials anonymously, but elects to give a loud public speech about how she's been bribed. It's just arrogance that she assumes she can win the Spellympics even when they're rigged against her.
Another episode (yes, Lisa gets these a lot) has Lisa cheating on a test, earning an A+++, which bumps up her school's average GPA to the point that the school earns a federal grant. However, at the ceremony for Lisa, she reveals to the audience that she cheated on the test. Yes, she's once again being honest even if it means that the other students won't get as good of an education because of it. However, Principal Skinner and the rest of the school staff anticipated that she'd do this, as the whole ceremony was a fake. They hold the ceremony a second time (without Lisa) and accept the grant money.
Charlotte of Making Fiends. She remains convinced that Vendetta is her best friend (despite Vendetta's constant attempts to kill her).
The ghost character Poindexter from an episode of Danny Phantom. Even though Danny is getting his revenge against Dash's bullying, Poindexter seems to think that Dash, the muscular jock in a lettermen, is the victim.
Silverbolt of Beast Wars is a Maximal with a sense of honor and nobility so overdeveloped that even the most idealistic of his comrades sometimes roll their eyes at his speeches and secretly wonder if his processor has a glitch.
He also consistently expects the (nominally evil) Blackarachnia to covert to the light side, despite her protestations. Even after she shoots him, he optimistically notes it was non-lethal. (In the end, he's right about her, but she gives him very little reason to believe in her.)
Then there's Binkie Muddlefoot, who tends to be this way a lot in the series. For example, one time when Darkwing tries to use his gas gun on Megavolt, she tries to stop him, claiming that guns are bad (despite the fact that it's a non-lethal weapon and the villain was trying to kill both of them).
Fluttershy from My Little Pony: Friendship Is Magic seems to have some Stupid Good tendencies. She has a habit of appending "please," "if it's okay with you," and "if you wouldn't mind" to every request, be it "do me a favor?", or "quit bullying my friends," or "stop destroying my home" (although the last of these was actually quite effective). In part two of the second season premiere, she snuck up on a sleeping Rainbow Dash who had been Brainwashed to be disloyal and hateful to her friends, only to politely wake her and ask if she wouldn't mind sitting still so they could forcibly tie her up and remove the curse, prompting a facehoof from Twilight Sparkle. It's finally addressed directly in the season 4 episode "It Ain't Easy Being Breezies" when it's made clear that sometimes one must be Cruel to Be Kind.
Although Fluttershy had already begun to deviate from her pure path in "Putting Your Hoof Down" (episode 45, or s2e19) when she dropped her stupid goodness in favour of asserting herself, initially to excess but in the end found a useful compromise and was able to politely refuse Iron Will the minotaur.
Due to his naďveté, Butters from South Park can teeter anywhere from mildly oblivious and gullible to Too Dumb to Live. This happens especially in "Butters' Very Own Episode".