Belldandy from Ah! My Goddess pretty much defines the concept of an impossibly pure-hearted person. That besides, in the Season 1 Finale against the Lord of Terror, when Keiichi is infected by the Lord of Terror and possessed, she offers to take his place as the host. Seeing the opportunity to get rid of the human body he was using, the Lord of Terror separated himself from Keiichi to infect Belldandy, but COULDN'T. She was simply far too pure. Because he had to move into something else, having detached himself, he moves into a nearby Floppy disk, leading to his defeat... at the hands of Skuld, armed with a small magnetic bar.
In the OVA, her angel is ripped out and replaced by a demon. Two minutes later, the demon radiates happiness and sparkles.
Or the fact that the most evilest thing she could think of doing, was jaywalking.
And Keiichi is no slouch, either.
Tomo from Seikon No Qwaser is a good example of this. She (while under her own influence and not Brainwashed and Crazy) has NEVER done anything remotely evil or malicious, and is so pure hearted Alexander is actually more drawn to her than the female protagonist at first. In fact, she's so pure hearted, the Ineffectual Sympathetic Villain finds it impossible to even attempt to do anything malicious to her as a result.
One of Kenshiro's defining traits in Fist of the North Star. Kenshiro does NOT do anything evil, will NOT tolerate any evil around him and trying to tempt him out of the righteous path will NOT end well for the offending party. He does, however, kill lots of people all the time.
Sailor Moon. Usagi Tsukino is the embodiment of unconditional love and forgiveness.
In Soul Eater Subverted: Justin Law is apparently naturally lacking in madness but ends up being corrupted and defects to follow the Kishin.
This is played straight and then averted with the titular heroine of Revolutionary Girl Utena. It almost seems as though she strives to be this because of her desire to become a prince. It also helps that she is thoroughly naive and often refuses to give a deeper look into the problems of the people surrounding her. Several characters try to take advantage of her because of this. Akio, who will sleep with anyone and whom Utena has fallen in love with, succeeds. She sleeps with him in a blink-and-you-miss-it scene from a clip show episode, of all things.
Battle Royale has the main character Shuuya, who despite the horrible things going on never gives up hope and faith in humanity. The novel and manga (but not film) also have Yuichirou Takiguchi, though his purity actually leads to deadly results.
You could also count Noriko Nakagawa, the most archetypal Mary Sue in manga history. She's similar in the movie and novel, but nowhere near so blatantly.
Son Goku from Dragon Ball. Apart from being able to ride the Nimbus, he also once survived an attack that worked by exploding one's heart with evil by the merit of not having a single shred of evil in him. His friends attributed this to him being really, really dumb.
Protagonist Nao Kanzaki in the manga series Liar Game not only acts as the moral compass for the other characters, she also never lies. As a consequence, she veers dangerously close to Purity Sue territory.
As of late, she has learned to lie, but still only for "the greater good."
Doctor Tenma from Monster. An example of this trope used exceedingly well. He is one part of the morality triangle in which Johann has given in to completely evil, and Nina dives into Grey and Gray Morality for all that it's worth.
Mutou Yugi in Yu-Gi-Oh! has this vibe going on. With the saving and the forgiving everybody all the time and big sweet eyes and not letting people get killed.
And apparently purifying the psycho spirit who possessed him, through soul contact alone, because "other-Yugi" stopped coming up with creative ways to get people to cheat and get either killed or insane, and turned into a normal (self-righteous and hyperdramatic) human being who happened to have a high school kid's body on timeshare.
Marina Ismail in Gundam 00 is an Actual Pacifist who refuses to kill anyone by any means and wishes to change the world by peaceful means if possible. She is notable for raising a group of orphans (a trait that defines her as an expy of Frau Bow) and even composing a song that heals whoever hears it, including the emotionally wounded Setsuna, who undergoes a Character Development into The Messiah for the rest of the 2nd season. At one point Marina even prevents one of her children from firing a pistol even at the cost of her own life, although her bodyguards later shoot down the villains trying to kill them, allowing them to escape.
Sajin Komamura from Bleach. It is revealed in his fight with Tosen that the entire reason he became his friend was because he wanted to provide a strong support so that the disillusioned Tosen might learn to love again. Sadly, it got worse, but Komamura still forgave him.
Cheza from Wolf's Rain is a pure character. She does not hate or do evil.
Hayate ofk Hayate the Combat Butler may be a very capable fighter, but any moral issues at best push him into a bumbling mess of nerves. Annoyances don't even corrupt him.
Noelle from Tenshi Ni Narumon is pretty much goodness and pureness incarnated - unfortunately with a side effect of having brain capacity of a 3 year old (while technically being 15).
Nana from Elfen Lied adheres to this entirely, never mind the fact that she is genetically predispositioned towards genocide, or the fact that she is always being made to suffer horribly. She's so good you could probably consider it a psychological disorder for her.
Comic Books
Dove in the DCU. Both the original and the legacy hero are so pure that in Blackest Night they are the only heroes who cannot be corrupted by the black rings.
First and foremost, Hartigan in Sin City. Largely a modern form of Galahad, the Perfect Knight. And he pulls it off in Sin City of all settings.
The third Blue Beetle, Jaime Reyes, is often shown to be the most pure of heart hero of his entire generation. A future Lex Luthor managed to corrupt most of the Teen Sidekicks and Legacy Heroes and came back in time to kill him because Jaime was one of the few heroes Lex couldn't corrupt, no matter what he did to the timeline. Also, Eclipso once tried to manifest Jaime's dark side by turning him into his darkest fantasies of power. Jaime turned into... a dentist.
"Hey! A dentist makes six figures a year! You can pay off your parents' mortgage, pay for Milagro's college. Sweet office. Nice car. Maybe even a vacation place down near grandma's in Mexico City—"
The list of people that Eclipso can't take over is absurdly small. However Eclipso was genuinely surprised at how little evil there was in Superman.
With most of the X-Men being a lineup of Anti Heroes, one exception stands out in the form of Colossus, a genuine Nice Guy and all 'round hero. His spirit is so pure that it (and the steel in his body) actually cause harm to most evil supernatural forces the X-Men fight. Just...don't tick him off. Seriously, don't.
Same with his good friend Nightcrawler; a deeply religious and good mutant who looks like a demon, who actually attempted to become a priest, and when faced with a Deal with the Devil tried to punch said devil in the face. He even makes friends with the incredibly Anti-Hero Wolverine.
Thor is often shown in this light as well. Only the purest of heart are able to wield his hammer. The list of people able to do so is pretty short (so far Beta Ray Bill, Captain America, Dr. Doom [huh?], Wonder Woman, Superman [the latter only sometimes] and a random paramedic who handed it to Thor before vanishing into the crowd. Dan Slott has claimed that, in the future, Eddie Brock will wind up bearing the mantle as a What-If?-type story).
Spider-Man is one of these. He always does the morally upright thing, even if doing so is insanely stupid (for example he constantly saves his attackers from deadly situations, and in the event of a villain vs. villain fight he'll side with the losing party to prevent one from killing the other).
He once defeated a villain that wanted to absorb and become him by the sheer force of his character - after defeating Spider-Man and having him at his mercy, the villain realized that he couldn't kill him and take his place since Spider-Man had never killed anyone, even in his decade long career as a crimefighter. He promptly gave up and left.
One of the driving forces of the character is that he is so strongly compelled to do what he sees as the right thing that he can't give up being a super hero, even with all the misery and ruined relationships that it brings to his life.
Captain Marvel from Fawcett/DC Comics. One of the common comparisons that happens since the Fawcett characters were added to the DCU is that even Superman fantasizes about just killing Lex Luthor and taking over the Earth for its own good from time to time. Captain Marvel is beyond that. It helps that he's still a kid
This depends on the writer, however, and sometimes Superman and Wonder Woman are shown possessing these traits as well. However if anyone is shown to be more pure than the Ur Example of The Cape, it's Captain Marvel.
The Justice League Unlimited episode "Clash" revolves around Captain Marvel as a new member of the League. He's portrayed as so innocent (and naive) that he makes Superman look rather paranoid and reactionary. He ends up leaving after (rather justly given the events of the episode) upbraiding the founding League members for not living up to their own standards.
Superman: I thought I was the boyscout. Batman: So did I... until I met Captain Marvel.
Actually, Superman was being insanely paranoid and reactionary. Much more so than usual.
In the comics, however, Superman tends to be a lot closer to this trope than his animated counterpart, mainly because he consciouslytries to be this due to fear about the amount of damage he could do with just one act of bad judgement.
The mega-crossover Underworld Unleashed had Neron, a Satan-Expy, going after the soul of Captain Marvel, because it was the most pure of the heroes. However, his soul was so pure a demon couldn't touch it.
Likewise, one of the major themes of Daredevil is invoking, subverting and playing with this trope. Matt Murdock created the Daredevil persona in order to rectify his Catholic faith with the fact that he saw evil to be fought against, distancing the actions from his "real" self. Just about every writer of the character since Frank Miller likes to put Murdock through hell just to show that while someone pure of heart may bend when confronted with the evils of the world, he won't break.
Oddly enough, of all people Norrin Radd, aka the Silver Surfer, often has this trait. Despite being the herald of a world-eatingEldritch Abomination. One of the reasons they call him Space Surfer Jesus.
Silver Surfer: I will not kill. Galactus: Yet you serve Galactus once more. Silver Surfer:I will not kill.
A What If? story predating the DC "Underworld" storyline above, but with a similar premise; arch-demon Mephisto finally gets his wish and wins the soul of the Silver Surfer, and drags him into Hell, only to find that the Surfer's soul is so pure that its goodness burns him —and since the Surfer agreed to be there forever, that light will always be burning Mephisto.
Rom Spaceknight is portrayed this way. Although most humans fear him upon first seeing him, pretty much anyone who gets to know him at all will end up marveling at his nobility and self-sacrifice. Even Namor, who tends to dis everyone he encounters, thought Rom was the most honorable man he'd ever met. Galactus claimed Rom was the only being he'd ever encountered who was as pure of heart as the Silver Surfer.
The premise of Incorruptible is that the supervillain Max Damage has decided to become an example of this after seeing the Plutonian become a Complete Monster in Irredeemable. He is Genre Savvy enough to realize that the world will fall apart without a Big Good like the Plutonian (before he went evil), and Max figured he might as well step up and fill the void.
Bart Allen, especially as Impulse, is made of everything good in the world. In 'The Future is Now' storyline, he chooses good over evil despite three of his oldest friends going bad in a WE ARE JUSTICE sorta way.
Fairy Tales
The Little Mermaid in the older versions of the story represented purity. She gave up her underwater kingdom, her wealth, and her fins all for love. At the end of the story she is unable to kill the Prince, even though he has fallen in love with a another woman. Refusing to murder him out of revenge she instead commits suicide, jumping into the sea and becoming sea foam.
Had not the creatures been venomous or been kissed by the witch, they would have been changed into red roses. At all events they became flowers, because they had rested on Eliza's head, and on her heart. She was too good and too innocent for witchcraft to have any power over her.
Film
Luke Skywalker in Star Wars turns out to be this in the end, contrary to what Darth Vader and Emperor Palpatine think.
Bail Organa, Leia's adoptive father and Senator of the Republic. An unwavering supporter of the rights of the people and of the Jedi Order, Bail puts himself in danger multiple times during the rise of the Empire by either criticizing Palpatine's policies or aiding the Jedi. When Order 66 began, the safe thing to do was to stay as far away from the Jedi as possible. What Bail did was head straight for the spaceport and embark on a mission to find any Jedi who had survived, and then to help them however he could. It was because of his incorruptible moral fiber that he became an enemy of the Empire and it eventually led to all of Alderaan being destroyed.
Scooby-Doo, according to the live action movie. It it for this specific reason the daemons go after him.
Joe Friday in the 1987 movie version of Dragnet (and arguably the TV version as well) is incorruptible. His only vice is cigarettes, which he warns others against taking up. Although as for pureness, at the very end of the movie he does end up with the virgin Connie Swail.
Eric Liddell in Chariots of Fire. Interestingly it is well done enough to make him more likable because of this instead of making him "sueish".
Utterly subverted in Monty Python and the Holy Grail, in that Sir Galahad wants to be corrupted after some convincing by the women of Castle Anthrax, only to be "saved" by Sir Lancelot just in time, much to his - and the women's - chagrin.
The fact that when Galahad was created Lancelot was his father always makes that sequence especially hilarious.
Jefferson Smith in Mr Smith Goes to Washington. He keeps his principles in the face of Washington corruption. And he suffers for it.
Astronaut John Glenn from The Right Stuff. "Mr. Clean the Marine" lived on the straight and narrow, was devoted to his shy, stuttering wife, and when he was approached by a couple of prostitutes who were working their way through the entire flight crew, he drove them away. (Even in the straight-laced 1950s he was considered remarkable.)
Ophelia and her baby brother from the movie Pan's Labyrinth both represent purity.
Batman in The Dark Knight is called incorruptible by Joker. Granted, Batman is the epitome of Good Is Not Nice, but Bats in the Nolanverse absolutely Will. Not. Kill.
While most of the knights in Thomas Malory's Le Morte d'Arthur are not exactly corrupt, when the Grail quest arrives, it finds that they are proud, violent, and unchaste. The honor of actually finding the Grail is reserved for Galahad, Percival and Bors. (Even Bors was not perfect, but was allowed because of the perfection of his repentance).
He precedes Malory, actually, but the idea of Galahad was generally that he was Too Good For This Sinful Earth, which is why he gets to ascend to Heaven while alive, and similar awesomeness. He is also distinguished by being verydull.
Literature
The Canterbury Tales does us a favor by introducing the characters in order of how pure and noble they are. The first character is a knight who is the epitome of perfection. He is spiritually perfect, and wears shabby clothes because he has transcended his desire for material possessions. Compare to the next few pilgrims, such as his son who is perfect but for his lust, and a nun who is devout but loves fine clothes.
Kendra, of Fablehaven. Because of her pure heart, she is not turned into dandelion fluff for entering the Fairy Queen's shrine. It comes in really handy when the end of the world as we know it is imminent (in all the following books).
Guan Yu from "Romance of the Three Kingdoms" is an incorruptible and extremely honorable character. When he manages to fight his way up to Cao Cao from the opposing army, Cao Cao, being unarmed, does not fear him, since he knows Guan Yu would never attack someone who was not prepared to defend himself.
Furthermore, he later captures Guan Yu and recruits him as an officer. However, Guan Yu states that he will return to the other side as soon as he finds his leader Liu Bei, despite Cao Cao constantly trying to tempt him to stay with elaborate gifts and promises of high status.
Carrot Ironfoundersson in Discworld, who has become less naive and more savvy but has retained all of his purity since coming to Ankh-Morpork. (Apart from his ability to become so terrifying people fall down to get out of his way when he flips his lid over his girlfriend leaving him... but he doesn't seem to know he's doing that.)
Additionally, Carrot's cynical boss Sam Vimes may be about as far from a Purity Sue as you can possibly get, but he's renowned the world over for being completely incorruptible. (In The Truth, after a couple of out of town criminals suggest bribing Vimes, the zombie lawyer Mr Slant responds with, "The last person who tried to bribe Commander Vimes is yet to regain full use of his fingers.") This is not out of a higher purity, but rather the development of a construct in his own mind to keep watch over his actions, created by his own willpower. Who watches the watchmen, indeed.
A short list of things Vimes has resisted: The Gonne (which corrupted everyone else who held it except its creator and Carrot), The Summoning Dark (a quasi-demonic entity of pure revenge which managed some control before being kicked out by said construct), and, several times, the urge to ignore the law, including one time when his boss was secretly standing behind him.
Even criminals know him as incorruptible, and consider him so even if he's not the sharpest knife in the drawer. He suspects privately that he's a spoon.
Brutha from Small Gods as well. He's the Moral Orel of Discworld. He is also essentially the Jesus-equivalent of his religion—except he manages to avoid the impending martyrdom, and hence the impending bloody crusades.
Aziraphale from Good Omens is supposed to be like this (well, he's an angel, after all) but Crowley manages to tempt him slightly away from the path of righteousness with classical composers and decent films (the only movie you can watch in Heaven, apparently, is The Sound of Music).
Tom and Eva from Uncle Tom's Cabin. This type of character was common when the book was written, but has fallen out of favor since.
A couple of these are featured in Charles Dickens' A Tale of Two Cities, namely Lucie Manette and Charles Darnay.
Absolute incorruptibility is one of the qualifying traits for Lensman. It is one of the hardest to find among human candidates, with only one hundred Earth Lensman graduating per year, though some other species have trouble even understanding the concept of corruptibility. (Though most of those races have troubles with other traits.)
The amazing frequency with which it is found in otherwise absurdlyGrimdark world of Warhammer 40,000 is one of the few reasons why the Imperium still stands. Unsurprisingly, novels set in this universe feature it quite often:
Ibram Gaunt from the Gaunt's Ghosts series. In one book, Major Rawne is urged to get himself out of Gaunt's regiment because Gaunt will get him killed, pointlessly, on a matter of honor, and that the Warmaster is amused by his old-fashioned honor.
While the reputation of Ciaphas Cain, HERO OF THE IMPERIUM, that states he can thwart all attempts at diminishing his loyalty to the Imperium is mostly an elaborate series of manipulations and half-truths (and his aide Jurgen, a psychic "blank" that cancels all Warp abilities), his faith in the God Emperor is absolute, and his faith in self-preservation is even stronger. Not only is he incredibly resilient to the mental manipulations of Chaos for an untrained and un-augmented human (although often their sheer level of power overwhelms him), he is also immune to the brutal and ruthless mentalities so prevalent in the Imperium, genuinely A Father to His Men (though he doesn't seem to realise it himself, claiming it to be part of the image he creates).
This is basically the whole schtick of Grey KnightsSpace Marine chapter. Their self-titled novel even has their commander (to bolster their Heroic Resolve) specifically invoking the fact that for the whole millenia-long history of their chapter not a single Grey Knight has ever fallen to Chaos. Which is no small stuff, given that all Grey Knights are psykers, and as such are much more prone to corruption, but still no other chapter can put a similar achievement under its belt.
In the third book, Alaric outwits a Daemon of Tzeentch by literally destroying every last facet of his mind and soul except the Grey Knight oath, then picking the pieces up again. His sheer strength of will defeated the machinations of an embodiment of the god of lies and trickery. Although said god was playing along to punish said embodiment for being lazy.
Medicae are particularly prone to this, such as Dorden and Curth in the Gaunt's Ghosts novels, and Arriott in the Ciaphas Cain novel Death or Glory. (Not invariably: a Jantine Patrician doctor in First & Onlydisdains treating a non-aristocratic soldier.) And Ravenor Returned features Belknap, who was unlicensed for serious malpractice because he defrauded the system to get medical help to those he should have rejected, such as children without registered parents. Believing Ravenor and his retinue to be criminals, he asks that they pay him by cutting loose the Street Urchin and giving him a little money to get out of a criminal life. When Ravenor asks whether Belknap can be trusted:
Patience: I reckon if you cut the doctor right through the middle, you would find the word "trust" written right through him.
Eisenhorn, the trilogy from which Ravenor originally spun off, subverts this trope. It features Godwyn Fischig, a member of the Arbites, as one of Eisenhorn's team. Fischig was so "straight up and down", as Eisenhorn said, that he betrays Eisenhorn to more puritanical members of the Inquisition when he realises - or thinks he realises - the full extent of Eisenhorn's radicalism. Although even there, he was clearly motivated by his desire to save Eisenhorn.
In the Horus Heresy novel Horus Rising, Loken's distaste for lodges and the Conflicting Loyalties and secrecy they bring is so pure that even a lodge member admires it, even as he is amused by it. In False Gods, when Loken is distressed by going up against rebels, their own people, rather than outsiders and worries about other rebellions, his friends intimidate they might report him for treason, and laugh at his reactions because he's so straight up and down.
In The Flight of the Eisenstein, Tarvitz's honor is what brings the great shock at The Reveal — and the willingness of the characters to believe him.
"Saul Tarvitz," whispered Sendek. "First Captain of the Emperor's Children. Impossible! He's a man of honour! If he's turned traitor, then the galaxy has gone insane!" Decius found he couldn't look away from Garro's shocked expression. "Perhaps it has." It was a long moment before Decius realized that the words has been his.
Nathaniel 'Straight Arrow' Garro fits well, too. There's a pattern to the protagonists of the Horus Heresy novels — unsurprisingly, considering the fact that the heresy was a tale of the corruption of the Imperium.
In the Ultramarines novel The Killing Ground, Uriel and Pasanius fall into the hands of the Grey Knights, who find it hard to believe that they escaped from the Eye of Terror untainted by Chaos, and test them with ordeals. They pass. Indeed, before the first, a mind probe, Leodegarius, the Grey Knight testing them, disbelieves protests of innocence and is even willing to torture to secure compliance, but after, he obviously wants them to pass the next two. After the second, when their wounds have healed as those of the innocent do, Leodegarius comments that he has never seen it happen so quickly. After the third, Leodegarius explains it was a Secret Test of Character —by defeating them he proved that they had no warp-based powers — and he had been confident that they could pass.
In the Blood Angels novel Deus Sanguinius, when Rafen emerges from his brother Arkio's schismatic forces and demands that Mephiston let him fight Arkio in single combat, Mephiston probes his mind and finds him made of duty and honour, having long outgrown a youthful arrogance. He steps aside for the much junior Blood Angel because no better champion could be found.
In the short shory "The Returned", many Doom Eagles are unwilling to even consider that Tarikus might be untainted, thinking he should be just executed for safety's sake. His old squad insist that he is pure even after being tormented for every waking moment for years by the foulest traitor-genius Chaos ever spawned, and their new sergeant points out they feel guilty about abandoning him. He passes all the tests and is declared pure.
In the White Scars novel Hunt for Voldorius, Voldorius taunts Malya with this: her incorruptible soul will remain intact, and she can therefore be used for his spell.
This is a trait shared by all the Heralds of Valdemar; they're famous for it. One cannot be Chosen as a Herald without it, or at least the potential for it, and the Companions make sure it stays intact. However, it must be noted that the Heralds are not plaster saints. They frequently suffer the downsides of Samaritan Syndrome (for some, like Vanyel, it goes all the way into Chronic Hero Syndrome), have interpersonal conflicts and moral crises like anyone else, and are anything but chaste. Further, they are first in the line of fire when Valdemar needs defending. While their Companions help them keep a moral compass, they also counsel against falling into the Lawful Stupid trap, and many a Herald is recruited from a shady or morally questionable background, including a con artist, a thief, an outland mercenary leader, an enemy officer, and more than one individual on their way to the gallows for murder.
Michael Carpenter from The Dresden Files, along with his fellow Knights of the Cross.
Harry himself seems like he would qualify. He spends two years being tempted by the shadow of a fallen angel. Eventually he converts the angel to good, or at least good enough to sacrifice herself to save him.
Important qualification; He converts the shadow, not the actual fallen angel. He hypothesizes that the actual angel would be as impossible to change as she claims, but as the shadow is imprinted in his mind, it's as malleable as that medium.
Later, Morgan, who unrelentingly harassed him when he feared Harry to be a warlock, comes to him for help. Lara even knows he is sheltering Morgan because people in trouble go to Harry, and Harry helps them. Though the White Council is bent on executing Morgan even if he might be innocent — politics demands — Harry sticks through thick and thin trying to exonerate him. After Morgan's Heroic Sacrifice, he does not try to argue with the Malicious Slander that portrays Morgan as a traitor, but he clearly regards it as Dirty Business.
William Laurence from the Temeraire series (Napoleonic wars fought with the addition of dragon-powered airforces). He's also brave, clean-living, thrifty and very astute - astute enough to understand the tension between Fair and Expedient. Oh, and his country is on the line. Angel walking through hell, anyone?
Marina from Pericles, Prince of Tyre. First off, she's so beautiful, sweet and talented that another character literally tries to have her killed for being too perfect. She mentions having cried after accidentally stepping on a worm. When she ends up in a brothel, she keeps her virginity by convincing every man who tries to bed her that he should follow the path of virtue instead. The brothel's owners let her go in disgust because she's driving them out of business.
Tycho Celchu, to the point where Wedge trusts him above anyone else. Suspected of being brainwashed and a secret traitor.
Lusankya conversion records: RI: Resistant in primary phase. Notes: Though the subject's initial response to Imperial icons was positive, this appeared to be an artifact of his years spent at the Imperial Academy. It did not last long. Subject aggressively attacked Imperial icons. When those icons were overlaid with Alliance datastreams, the contradiction caused the subject to become catatonic. Subject is unsuitable for conversion.
This is proved beyond a doubt with the way he handles the trial.
Darryl McAllister from Diane Duane's Young Wizards series. As an Abdal, an avatar of the One, he directly channels the One's energy for pure good.
"Reality might hit him, might, indeed, have hit him hard already — but it might be what shattered."
Sofia Marmaledova is also unusual for being the rare overlap between Incorruptible Pure Pureness and Hooker with a Heart of Gold.
In How I Live Now by Meg Rosoff, the American teenage heroine is sent to live with her English cousins on the eve of World War Three. Nearly all her newfound relatives are full of Incorruptible Pure Pureness, especially 9-year-old Piper, and 14-year-old Edmond, with whom the heroine falls in love.
"If anyone feels like arresting me for corrupting an innocent kid then all I can say is Edmond was not corruptible. Some people are just like that and if you don't believe me it just means you've never met one of them for yourself. Which is your loss."
There are a lot of individual moments that would make one question this, including outright mental health troubles, but, seriously, Drizzt Do'Urden. He was raised in an Always Chaotic Evil city, escaped it and lived for years as shunned and in harsh conditions before being accepted by anyone at all, and after that has lived a life that has constantly involved violence by necessity. And yet, just listen to him. Most people couldn't sound like a more exaggerated saintly hero if they tried, and he's entirely sincere.
John Hemry's Paul Sinclair. In A Just Determination, he testifies on behalf of a captain whom he neither liked nor respected, did not think a good officer, and never wanted to serve under again, because while the man had done wrong, he was being hammered. By the fourth book, Against All Enemies, another character explains to him that his superior finds it a little intimidating to have a subordinate with such a reputation for always doing the right thing.
In The Lord of the Rings, several people are able to overcome the temptation of claiming the One Ring for themselves, or simply are not tempted at all. In the movies, the One Ring's powers of seduction are dialed Up to Eleven to be almost active rather than passive and the characters' reactions are adjusted accordingly.
Faramir, despite what some might claim, is tempted by the Ring in the original. When he finds out Frodo has it, he smiles strangely, slowly thinks out loud that the Ring is in his hands and the hobbits at his mercy (just two of them against a force of men at his command, etc.), his eyes gleam, and he draws up to his full height. This alarms the hobbits who rach for their swords. However, Faramir rejects the Ring, because:
He's more Genre Savvy than his movie counterpart - he's enlightened enough to know better than to use it. He's already more 'aware', so to speak, of the temptations of evil than his brother Boromir was, because he's been tutored by Gandalf in the past.
He gave his word not to claim it and that was considered serious business - see the undead army of oath-breakers later on.
Also, he never actually sees the One Ring unlike the movies. So it's not so surprising that as a wise, enlightened, decent man, he had relatively little trouble pressing aside the temptation.
Gandalf and Galadriel are tempted at Bag End and Lothorien, but they are able to resist because they, like Faramir, are Wise with a capital W. Galadriel also doesn't go radioactive.
At one point Sam has the Ring all to himself, and the Ring gives him visions of becoming a mighty lord, overthrowing Sauron and transforming Mordor from a wasteland to a gigantic garden. But Sam rejects this because he only wants to tend a garden on his own, not to lord it over others (and have them do the gardening).
And Sam Gamgee doesn't even think that his resisting the Ring is a big deal. As far as he's concerned, it's just plain hobbit common sense. His main reaction is to pity Frodo for having to endure such temptations for months on end.
And Tom Bombadil is not tempted by the ring at all, and is probably the truest example of Incorruptible Pure Pureness in the book, but that's because he was either significantly older than the Ring or in a whole other ballpark power-wise (see the WMG for Lord of the Rings).
Deconstructed by Galad in The Wheel of Time after he inadvertanetly sparks a city destroying riot (with a side helping of war) to help his sister.
Unless you count her brief foray into normality (or, at least, her own brand of normality), Jerry Spinelli's Stargirl could be considered incorruptible.
Jane from Pride and Prejudice. Throughout the entire thing, she was the most pure, incorruptible character, constantly believing in the good of everyone (yes, everyone). It drives her sister, the heroine, crazy.
In The Bible, Jesus is offered dominion over all the Earth if He'll just bow down and worship Satan. His response is predictable, given that it's Jesus.
Other Biblical examples include Abraham, Noah, and Daniel, just to name a few. In fact, most religions regard their respective founders, leaders, and notable figures to be similarly pure.
So spake the Seraph Abdiel, faithful found Among the faithless, faithful only he; Among innumerable false, unmoved, Unshaken, unseduced, unterrified, His loyalty he kept, his love, his zeal;
Arthur, from Keys to the Kingdom, spends a great deal of time trying to be this, both physically & mentally. He does have some moments where he fails—big time. To be fair, it's not easy when magical forces that literally run the universe are trying to assert their dominance over you. As far as personal will goes, he never chooses to do anything malevolent or be dissuaded from his course of action.
Ten Ox from Bridge Of Birds. Master Li says that he suffers from "an incurable case of purity of heart". It's also the reason for him subconsciously recognizing and worshipping Lotus Cloud as a goddess in disguise, whereas Master Li, the one with a "slight flaw in his character", did not for a long time.
Live Action TV
Kenneth the page in 30 Rock retains his sunny optimism despite being surrounded by unscrupulous business men and jaded industry types.
Probably the best example is the season 4 finale, in which he is unjustly fired. He crashes a party and announces that he's finally going to tell everyone present how he really feels about them and the way they have treated him over the years...he loved every minute of it and will see them all in heaven. Combines Crowning Moment of Funny and Crowning Moment of Heartwarming.
In another episode, Jack, who is actively trying to corrupt Kenneth and test his virtue, traps him in an elevator with eight other people and informs him that since there is only enough oxygen for eight to survive long enough to be rescued, one person has to die (via the conveniently placed pistol in the phonebox). Kenneth immediately grabs the pistol and tries to blow his own brains out, and when it turns out to be unloaded (duh), tries to strangle himself with his belt. This causes Jack to flee from the elevator, completely unnerved and spluttering "What is wrong with you??"
Fred Rogers might very well have been a real-life version of this trope. Let's face it, the man was just GOOD. Pure and simple.
The 1998 Merlin series repeatedly subverts this, as Vortigern, Uther, Lancelot, and Guinevere do not turn out to be the saintly people they were originally thought to be. Played straight with Arthur, however, and implied with Galahad.
Arguably the Groosalugg in Angel. He's noble, strong, brave (to the point of almost being stupid). The worst sin he commits during the whole series is being mildly jealous of Cordelias love of Angel.
Captain Sheridan in Babylon 5, so much so that in the show's universe he becomes a mythical figure himself, after Earth is bombed back to the middle ages.
Edith Bunker in All in the Family is sweet and nice to everyone and completely honest, providing a contrast to her bigoted, Jerk Ass husband, Archie, whom she puts up with with endless patience. In the episode "Archie and Edith Alone", Archie even calls out her for it: "Good thing, that's you all over! Always doing good! Edith the Good! You never get mad at nobody, you never holler at nobody, you never swear, no, nothing! You're like a saint, Edith! You think it's fun living with a saint? It ain't!" He challanges her to "do something rotten"; she tries to insult him, then crash a bowl of flowers, but she's literally unable to do either.
Rick from The Walking Dead refuses to betray his ideals or leave a man - even a jerk like Merle - behind.
Ximena Fernandez, the teacher from Carrusel. She never does anything objectionable and is always kind and follows her good morals. Also, Daniel Zapata and Carmen Carrillo never seem to get into trouble, are kind to everyone, and do well in school.
John Cena is commonly portrayed as this, and for the most part he really is. However, he's still a thug at heart, and will occasionally Pay Evil unto Evil if you get him angry enough.
His current feud with Kane hinges on the big monster attempting to get Cena to "embrace the hate", in order to corrupt him, as it were.
Kelly Kelly and Eve Torres. The only two major Divas in modern WWE history to have never, ever been heels.
Sting. (He has been a heel a few times, but many fans either don't remember or don't care.
Tabletop Games
In the 1st through 3rd Editions of Dungeons and Dragons, members of the Paladin class were required to maintain their Incorruptible Pure Pureness or lose their class abilities. Unfortunately, many problems arose when people played them as merciless, smite-happy, Lawful StupidKnight Templars and GMs didn't call them on it, or when GMs interpreted even the slightest bit of grey morality as an excuse to strip the paladin of their powers and players didn't call them on it. 4th Edition abolished this restriction, but they are expected to stay in line with the ideals of their patron god (so if your patron god expects you to be a bastion of Incorruptible Pure Pureness, then think twice about putting the orc kids to death. If your patron god is a slaughter-happy maniac, then think twice about petting those puppies unless you intend to snap their necks while doing so)
3.5 has a series of feats for monks that grant absurd bonuses if they follow incredibly strict disciplines. The feat Vow of Poverty is the most extreme one, which grants the character a few bonuses in exchange for them never owning any material possessions save for the very basic essentials. The result is a character who will never break his chosen vow no matter what.
That's not a monk-only feat. Vow of Poverty, along with Vow of Peace (a feat requiring you to never deal lethal injury to a living thing, in exchange for tremendous numerical bonuses) appear in the Book of Exalted Deeds, and anybody can take them. Enforcing 'fluff' rules (like non-mechanical penalties for starvation) is the only thing that limits them (other than the whole "can't lethally injure something or own shinies" things).
Anybody who remains Exalted, (i.e. To Good characters what regular Good characters are to Neutral ones) on top of the additional restrictions for the Vow itself, yes.
The end of 3.5 gave us Heroes of Horror and the near-definitive ruleset for the taint of evil, which treated evil that was vile enough as a physical thing that could corrupt the bodies and minds of characters. Characters with the Pure Soul feat were incorruptible, and immune to taint.
Ravenloft has a class of characters called "Innocents" who share this trait. They get a certain amount of protection from the horrors of the Demiplane of Dread, but they lose it if they do evil or even get exposed to it in certain circumstances. The goal of the PCs is usually to keep that from happening. There's also a "True Innocent" Prestige Class that jacks this up to eleven. Paladins are brought back closer to this trope as well in said campaign setting: Paladins are literally such beacons of goodness that they slightly dissolve the fabric of Ravenloft itself enough to make the various Darklords able to sense their general location...
While Warhammer tends to subvert these kinds of characters whenever they can, the High Elf Everqueen seems relatively immune. Helps being Friend to All Living Things, and she's so pure her very presence dissolves demons and dark magics. Naturally she tends to be a Distressed Damsel.
Outside of Warhammer 40,000 literature mentioned above, there were the Sensei, descendants of the Emperor who can't even have negative feelings like hate and envy, and the Star Child, the incorruptible innocence of the Emperor that he had to discard in order to kill his favourite son after purging him of all the evils that lead to the fighting.
The Grey Knights Chapter subjects its recruits to the equivalent of 666 Mind Rapes as part of their training, then erases their personalities at the end of it, on top of the nightmarish training regimes of a Space Marine, ensuring their complete incorruptibility. For the whole millenia-long history of their chapter not a single Grey Knight has ever fallen to Chaos, despite this being a setting where reading the wrong book or talking to the wrong person leaves one open to Chaos taint. Supposedly their purity and piety is so extreme that demons find it physically painful to even get near them (apart from the physical pain caused by the boltguns and flamethrowers, that is).
The Sistersof Battle, despite what the majority of fan-fiction seems to want, have had only a single Sister fall after many thousands of years of constantly battling Chaos.
Darnath Lysander, Captain of the Imperial Fists 1st Company, was lost in the Warp for a millennium. When he finally got spat out again, he was captured by the Chapter's arch-enemies and tortured. He broke out of his prison, unarmed, and returned to his Chapter. The Chaplains and Apothecaries tested him for six months for any sign of taint. He passed, and was given command of his old company. He then proceeded to hand the asses of his captors to them on a silver platter.
The thirteenth company of the Space Wolves have been fighting in the Eye of Terror, uncorrupted, for approximately ten thousand years.
Though that has a lot to do with them being already corrupted in a different way.
Deconstructed by the Unconquered Sun in Exalted. He's pure in four different ways that don't interact well, and deals with the stress by hanging out playing the Games of Divinity for, oh...about the last two thousand years.
Theater
Sarah Brown from Guys and Dolls is an example of this, and this trope is parodied by her mission band's inability to "save" any souls until Sky makes the other gamblers come to the testimonial
The protagonist Violane in the play L'Annonce faite à Marie (The Tidings Brought to Mary) by Paul Claudel. Violane is moved by pity to kiss a leper, and gives him her engagement ring to help financing the church. This of course does not sit well with her fiancée Jacques — especially now that she has contracted leprosy herself. Jacques marries Violane's sister instead, but when their child dies, the saintly Violane, blind and forsaken in the lepers' colony, brings the kid back to life.
Daesdaemona in William Shakespeare's Othello is the embodiment of rational virtue. As such, she is as incorruptible as it gets.
Video Games
Terra Branford, of Final Fantasy VI. While she was mentally enslaved by the Empire and forced to do horrible things while being controlled, when she is freed she later becomes a pure hearted protector. She ends up caring for a group of orphans in Mobliz whose parents were murdered by Kefka after the Apocalypse. Once she finds out who she is, she becomes a protector, who fights not to kill, but to protect and to ensure hope. Completely driven by love, she never has hatred in her heart.
Co-star Celes Chere is described as having a spirit as pure as snow, but she plays more of The Atoner as she has done past evil actions under free will due to being a general for the Empire. It can be said that she does fall under this trope later in the game, as the Empire tries to bring her back to their side on the Floating Island, but she refuses.
Aerith of Final Fantasy VII is probably the only person alive in the world who could get The Planet to condone a Holy, besides the fact that she's the only person alive with the means and knowledge of how to do so. Nevertheless it seems that this might have been common among the Cetra when there were a lot of them.
The Links in general are described as having pure hearts. Combined with the Triforce of Courage, it's why only he/they can wield the Master Sword.
In Twilight Princess he is forcibly transformed into a wolf. Even in this bestial form, various characters note that it hasn't diminished his nobility one bit.
Interestingly enough, those characters who DON'T freak out when they see Wolf Link are usually innocent characters themselves (Agitha the wide-eyed bug collector, the innocent simpleton lantern salesman at Faron, among others)
Princess Zelda herself also qualifies; in the linked games of Oracle of Ages and Oracle of Seasons, she is specifically sought by the villain to be a human sacrifice for this precise reason.
The whole point of Ultima IV is for the main protagonist to become this.
The Princesses of the Heart from Kingdom Hearts (Alice, Jasmine, Snow White, Belle, Cinderella, Aurora and Kairi) are, by definition, seven maidens of Incorruptible Pure Pureness. In Birth by Sleep, several characters observe that Ventus's heart is similar to theirs - because his corruptible impureness was removed and molded into Vanitas a few years earlier.
Both Sora and Mickey.
Aqua, being the only keybearer of the BBS Power Trio to achieve the rank of Keyblade Master. Her purity isn't quite as much a part of her character as it is with Ventus or Sora, but it was still sufficient to allow her to survive for more than a decade in the Realm of Darkness without her armor or her normal keyblade.
Adell from Disgaea 2, at least by the standards of the Disgaea universe.
Nanako Dojima of Persona 4, perhaps by virtue of being 7 years old, loves everyone unconditionally and sincerely. The only person not to manifest a Shadow when thrown into the TV world, though whether it's because she's that pure or because she's too young to have fully manifested her ego is unknown.
Imoen does take a turn for the morbid at times, but her genuine cheer and goodness was, apparently, enough to keep the piece of the God of Murder inside her at bay.
Princess Peach, especially in the RPG games. In the first Paper Mario game, her love for her kingdom is enough to counter Bowser's defensive spell, and in the second one her purity is what makes her the chosen vessel for the Shadow Queen.
The eight potential player characters in Darkstone are known as the Pure of Heart, a group of special fighters whose souls cannot be tainted by evil.
Marth and his love interest Caeda were portrayed like this in Fire EmblemShadow Dragon, and especially Mystery of the Emblem. He pretty much was fair to everybody and was always innocent minded despite the evil things that happened to and around them.
Paz from Metal Gear Solid: Peace Walker is a subversion, since she's really a nihilistic mole for The Patriots and was just using the Incorruptible Pure Pureness personality as a cover.
Byakuren Hijiri of Touhou is probably a Deconstruction of this trope. Sure, she's like Mahatma Gandhi and Martin Luther King Jr. combined, but even ZUN questions whether her equality paradigm makes a lick of sense in Gensoukyou, where humans are basically at the mercy of the youkai that outnumber and outpower them.
Kasen Ibara strives to be this trope incarnate, with mixed results. One hand missing notwithstanding...
Hermits must follow the training of Shuugyou (abandoning worldly desires to pursue enlightenment) in order to preserve their existence. It is far more difficult than being a celestial, as they must be diligent in their training lest an assassin from Hell comes every century to kill them as their powers weaken when they stray or they will even turn to ash. The Touhou universe is more lenient with them.
How about an entire species of Incorruptible Pure Pureness then? I'm talking about the Pokémon Absol. They watch humanity from their mountain dwellings only to warn us disasters both natural and man made. And what do we do to repay them? The human villagers falsely and mistakenly accuse them of causing these disasters then persecute and abuse them. Yet they still warn us in hope that one day we'll finally pay attention and heed their warnings. If that's not Incorruptible Pure Pureness I don't know what is.
In Fate/stay night, Gilgamesh is this. Technically. In a shocking moment of Pure Is Not Good, Gilgamesh reveals he managed to stop '''all the evils of the world''' corrupting him when he was hit by the Holy Grail's curse via his willpower and 'purity'. Given his typicalbehaviortowardseveryoneelse (especiallySaber), fans tend to agree that the only way he can be seen as pure is as a 'purely amoral and self-centered sociopath'. Fate!Shirou manages to be this, surviving the same curse by will alone once, then using Avalon to block it when it hit him a second time.
From her official bio: Piffany is the epitome of goodness, sweetness, and light. Her birth was said to be heralded by rainbows, songbirds singing in three-part harmony, and her entire village having a "nice day." She was given to her clerical order by her parents, who reportedly were sleep-deprived due to Piffany's 300-watt halo of purity keeping them (and most surrounding farm animals) awake at night.
Suffice it to say, Piffany is such a pure example of this trope, there's justification to rename it "The Piffany".
Kiki from Sluggy Freelance has never intentionally caused anyone any harm and seems to love everyone. Unfortunately, she's also a collossal idiot and Genki Girl, so the amount of harm she causes unintentionally can be quite staggering.
Her counterpart Good Bun-Bun from the Dimension of Lame has a similar purity, although he's smarter than she is. Actually, all of the people in that dimension are completely non-violent, kindhearted and incorruptible, which turns out not to be a good thing. When he's about to leave that world, Torg said to Good Bun-Bun, "You're the only one who's been straight with me in this entire world."
Despite never having been referred to as being Incorruptibly Pure, Elan from Order of the Stick is pretty clearly this, especially recently. He's too naive/innocent/adorably ditzy to even dream of committing evil acts.
To the point where he's a little morally torn by the fact that he had to steal new clothes after escaping from prison. Haley (the rogue)'s reaction to this is... enthusiastic.
O-Chul is another good example. Even after being imprisoned and tortured for months, he sticks to the Paladin code and is ultimately rescued with his honor intact.
After his Magic World adventure, the citizens of Reality have declared Todo this, calling him "The Soul of Reality."
Jesus, Buddha, and Criminy in Sin Fest. While Jesus and Buddha are self-explanatory, Criminy is a young, nerdy bookworm. Fuchsia, a servant of the Devil, has fallen in love with him and shifted from Chaotic Evil to nearly Neutral Good as a result.
Somewhat subverted or parodied with Joyce from the Walkyverse. She was so innocent that she was the only one immune to the Aliens' torture of choice: being forced to watch The Sound of Music. So they showed her pornography instead. Despite being a college student, she had no idea of how human sexuality worked, and this messed her up so badly that she used an alien memory erasure device to delete all her memories, and it takes her years to get them back. Although she has since matured to the point where "pre-marital hanky-panky" no longer bothers her (and she frequently engages in such with her fiance Walky), she is still the nicest, sweetest, most innocent person you are likely to ever meet.
Claire of Sister Claire has but one vice in all the world; she loves cats, and can't help stopping to play with them should she meet any outside the walls of the convent (which is actually more serious than you might think, since the nun who is her mentor and mother-figure is flagrantly allergic to cats and even a little bit of fur on Claire's clothes will cause her to swell up like something funny that swells up really big). She's vaguely aware of the existence of evil but has difficulty conceiving of it in others (with the possible exception of Sister Marguerite, with whom an antagonistic relationship would be an improvement for poor Claire). Her chipper innocence almost gets her in serious trouble when Gabrielle takes her to a supernatural nightclub.
Western Animation
Optimus Prime. There's a reason no other leader of the Autobots has gone uncontested.
Moral Orel, as stated in the above quote. Orel lives in a Crapsack World of Stepford Smilers but continues to be a genuinely nice, moral, faithful, and kind person... and it pisses his father off to no end.
Even when demonstrated to not be fully immune to corruption it is never his fault, due to some adult giving him terrible advice.
Butters Stotch. South Park keeps on using him as The Chew Toy, but he remains relatively well-adjusted despite almost hitting the breaking point a couple of times. Even when he tries to be evil, he fails miserably.
Samurai Jack, to the point where he was able to resist being stabbed through the chest by his own weapon because of his purity.
There was a notable instance of Aku manifesting Jack's evils (anger and battle-lust - basically the sin of Wrath) as a dark Jack, and Jack defeated him by simply calming down and purging himself of those thoughts. Not completely incorruptible, but very close.
Aang of Avatar: The Last Airbender aims for this. He has faltered (especially when Appa and Katara were endangered), but in the end he achieves this.
The Zeta Project gives us Zeta, who in essence becomes this after his moral epiphany during the pilot. Though he did immoral things before hand, once he obtains sentience he becomes a soft spoken, loving, gentle, compassionate person who is innocent to the ways of the world. He seems to have a self imposed moral code of never killing anyone and doing his best not to hurt anybody, and his sincerest wish is to live his life peacefully.
The Duke of Nuts from Adventure Time. Despite a crippling pudding deficiency that causes him to occasionally steal pudding from Princess Bubblegum (and earn her undying hatred), the Duke is shown to be a genuinely good soul, going so far as trying to turn himself in for a crime he didn't commit just so Finn and Jake wouldn't get in trouble. It should be noted his first time offering this was while helping a family of ducks across a pond with his own cloak.
The Flash in Justice League. Word Of God said that they had to kill him off in the Justice Lord timeline because they couldn't think of anything that would make him willingly Face Heel Turn. In-universe, Wally's absence is what lets the normally incorruptible League fall off the path.
In My Little Pony Friendship Is Magic, Discord goes out to corrupt the mane six. He manages to corrupt five of them through rather subtle Mind Rape. Fluttershy, however, is so pure and nice, that he has to just brainwash her with brute force.
Princess Celestia, probably. We've only seen her get even slightly angry twice, and both were rather extreme circumstances. The return of a tyrannical, reality warping, anthropomorphic personification who wanted to make existence a living hell for all her subjects, and her favorite student inadvertently brainwashing the whole town into a brawl simply so she could complete a school assignment. All other times, Celestia has shown the patience and virtue of a saint, and was rather forgiving on the second mentioned occasion.