In Ghosts of the Past, sequel of Child of the Storm, Harry's refusal to give in to the temptation to use the Phoenix fragment/become the Dark Phoenix to rescue Carol during the Bloody Hell arc is cited as this. It's considered particularly remarkable, as it came despite extreme provocation (two of his friends are almost killed, one maimed) and desperate circumstances, all of which giving in to that particular temptation could have solved more or less instantly, as well as whose life was on the line. Instead, he chose to do what was right, rather than what was easy.
In the Love Hina cross-over fanfic Contract Labor, this is the reason why Keitaro risked his life by going to Roanapur in what almost everyone considers a suicide mission to rescue Sarah McDougal, a young girl who does not like or respect him, who may be already be dead or beyond recovery. As Keitaro said before he left, "I knew what I was doing when I made that promise. Even if you release me from it, I would know that I did not do my best to get Sarah back. I would have to live with myself in the dark with that knowledge. I won't. I can't."
In Rabbit of the Moon, Bell is thoroughly exhausted in every way after killing Gascoigne and is elated to discover that he can return home to Orario. But after thinking about Gascoigne's daughter, he can't find it in him to go home when she's still waiting for her parents. So he ends up staying to search for her mother and later escorts the girl to Oedon Chapel after discovering Viola's remains. Only after the Little Girl is safe does he return to the Hunter's Dream and then Orario.
In the Infinity Crisis spin-off/sequel Brothers of Thunder, Lokia- a female version of Loki from the gender-inverted Earth-911111- only realises that she's picked up her sister's Mjolnir when she's already holding it, although the hammer is still too heavy for her to be sure of using its power and she puts it down before anyone else sees her holding it.
In Suzumiya Haruhi No Index, Kyon could have left Mugino, who had been trying to kill him, to be killed by the Celestial while they were both in Closed Space, but he instead saves her. It pays off because she falls for him.
In The Bridge: Big Good Godzilla Junior is grappling with worries that he is not that different from his highly destructive, revenge driven father despite honestly trying to be heroic. Psychologist Moonbeam Glimmer manages to hit all his buttons in the worst way possible in front of a live audience in a misguided attempt to show he's too dangerous to be around the public and that he is more psychologically damaged than he thinks. Junior later finds out about Glimmer's history, where her being too trusting of someone with power got her family murdered, and tracks her down to her parents' graves she was visiting in a completely isolated area. They were entirely alone, he still has all of his powers as a stallion while she was a normal mare, and when she finds out who she was alone with she realizes he could very easily exact his revenge. Instead Junior proves he's not like his father by placing some flowers on the graves, whispering that he understands and forgives her, and saying she can come to him to talk later if she needs to.
SAPR: The infamous Breach in the chapter "Defined By Choice" has the moment for Sunset. Turns out she wasn't a hero after all.
Equestria Girls: A Fairly Odd Friendship: Timmy is given a choice by the Dazzlings: he can grant them what they want and rule at their side, or he could lose his fairies. Without knowing the Rainbooms are listening in, he furiously refuses to help them, not wanting Cosmo and Wanda to be reduced to magical batteries.
Essentially applies to Max's actions in Unexpected, where Max and Caroline met a year before Caroline's father was arrested, allowing Caroline to set up the cupcake shop for Max just because she admired Max's skills. After news of Martin Channing's arrest goes out, none of Caroline's rich friends bother returning her calls, but Max not only calls Caroline but offers her a place to stay even when she believed that she was going to lose the cupcake shop and any money Caroline might have given her (in reality, Caroline had signed everything over to Max and Max just hadn't realised because she never checks her bank statements).
A public example of this occurs in the The Dark Knight fanfic Legend; the Joker has captured Gotham police officer Anna Ramierez, the woman who helped the mob capture Rachel Dawes and Harvey Dent, and hence one of the few people who knows what happened to Dent and thus has reason to suspect that Batman wasn't the one who killed the people Dent went on to kill. The Joker then televises his subsequent torture of Ramierez with the goal of getting her to confess that Dent was the one who committed the murders, thus destroying Gotham's faith in him and everything that's been accomplished in his name... but instead, on live TV, Ramierez claims that she committed the murders, destroying her reputation and condemning herself to death as the Joker beats her in a fit of rage, knowing that only a few people such as Commissioner Gordon and Batman will ever know the truth about what she did. Her funeral is attended by only a half-dozen people with no regard for the usual honours given to a police officer who fell in the line of duty, but it is noted in the narrative that those who know the truth will forever judge Ramierez by her final acts, with James Gordon attending the funeral with the other public mourners and Bruce Wayne watching from the distance long after everyone else has gone.
In Ties That Bind, Faith basically passes one for her long-unknown daughter Eleanor; Eleanor was conceived when an agent of the Watcher's Council had Faith raped as a teenager because it was foretold that her daughter would play an important part in a soon-to-be-fulfilled prophecy and the baby was abducted after the birth, but Eleanor has spent years believing that Faith abandoned her willingly. When the Scoobies learn about the extent of Travers' plans for Eleanor, Faith asks the gang not to tell Eleanor the truth because she wants to protect her daughter's image of Travers, but she is unaware that Eleanor was right outside the door listening to them, and Faith's shock reaction when she finds Eleanor outside the door affirms to Eleanor that everything she heard was the truth.
Whistler in Preconceptions has his charge changed from Angel to Xander but has a moment where Xander seems to be going against the plan laid out for him. Whistler realizes he could nudge Xander onto the "correct" path with no consequences but he swore not to interfere and is determined to keep his word.
Zero/Lelouch decides in The Black Emperor that converting Suzaku is a lost cause when the latter refers to the Japanese as Elevens in a discussion between the two of them. Even though the only people around were those sympathetic to the Japanese, he still refers to them by the "name" given to them by Britannia.
let's go out with a bang!: After joining the Enforcement Team's efforts to instill order in the locked-down convention center, feeling more accepted among their number than she is by her fellow alumni from V3, Miu is given a gun and ordered to help ensure that they meet the hostage takers' demands. She finds Kokichi, the one she blames the most for her isolation, hiding alone. He taunts her, challenging her to pull the trigger and prove that he was right all along: that she was already Beyond Redemption. To their mutual surprise, Miu can't bring herself to do it, and her tearful confession of how much he terrifies and haunts her forces him to have a Heel Realization.
In Resurrected Memories: :Ember's HeelFace Turn is put to the test in chapter 38, appropriately called Temptations. Here Ember, being confused over how real her friendship is with Danny and having discovered from Star a major secret that could get Paulina expelled but has promised to keep it quiet, is very confused. That night she has a dream where she is confronted by a representation of her former self, who tries to tempt her into taking advantage of her situation by using the information from Star to win the bet, as well as use her situation to use her powers from her fans in order to take over the world. For a moment, Ember is tempted, only to remember how much she has grown to care about Danny, how he genuinely trusts her and she remembers that if she tells, she may very well end up ruining Star's high school life in the process. Ember remains firms and tells her alter ego point blank that she will not betray Danny or Star's trust, thus cementing her HeelFace Turn for good.
Fade: Light quickly figures out that Near was his killer in the story, and deduces that he might also know that both he and L are Kira. In spite of all that, he refuses to kill Near or tell L, and begs L not to either when Near confronts them via broadcast, as all he is doing is opposing them he has yet to commit any actual crimes. This shows that this Light still has morals, integrity, and above all else, humanity. It's no wonder why Beyond is so intent on saving him.
Final Fantasy VII Another Side: After shooting down the Turks' helicopter, Cissnei thinks back to a conversation she had with another ex-Turk about why she'd getting so involved with AVALANCHE. When said former colleague demands to know if she thinks she can erase all her dark deeds of the past or if she wants to be a hero, Cissnei replies, "It's not about being a hero...it's about being able to look at myself in the mirror."
In Shadows of the Mind, Cloud becomes convinced that Lazard is giving away Shinra secrets (or at least knows something about it and is refusing to investigatte), secrets that eventually got a battalion of his comrades killed. When Cloud decides to investigate, Snow offers that they could just go back home right now, which no one would ever find out about. Cloud refuses.
Snow: Nobody would ever know if we walked. Cloud: We'd know.
Corrin Reacts: Flora encounters this situation in the past when Corrin attempts to rescue her from a canyon she'd fallen into and nearly dies from exposure to the raging blizzard, despite loathing Corrin and chewing him out for his (as it turns out, unintentional) participation in her being held hostage at the Northern Fortress. Instead of leaving him to die, Flora goes to save his life and later becomes Fire-Forged Friends with him. It's implied she still feels massively guilty about this incident.
In A Father's Courage, Harry's baby daughter is being cared for by Madame Pomfrey while he's sick with dragon pox at Saint Mungo's. Draco receives a message telling him to kidnap the child and send her to Voldemort. He takes her from the hospital wing unnoticed, places her in the Vanishing Cabinet and is about to cast the spell to transport her when he has a fit of conscience and decides to return her to the hospital wing.
In His Honor, The Mayor, Drew Lipsky? when Bonnie is taking part in a fashion show with her family in the audience she sees Kim trying to push a large gas tank with a timer into an airtight room, she connects the dots and helps push the tank, and when it becomes obvious that there's not enough time for them to run outside and lock the door behind them before the timer hits zero she locks them both inside fortunately, the payload is nonlethal, unfortunately the payload is Nanomoths.
In Splint, when Rukhash first finds Cadoc - who is badly wounded and unconcious - she seriously considers killing him purely because he's a Man and to get revenge for everything his race have done to her and other Orcs over the years. She doesn't. As she later tells him:
"I thought for a moment to take that out on you while you were bleeding out, but I didn't. I didn't blame you because that weren't fair, because I didn't think it were right to make you pay for shit you didn't do".
In Two Spiders on a Web, multiple women proposition Spider-Man despite the fact that they know he's already in a relationship with Spider-Gwen. They even cite the classic phrase of "she doesn't have to know". Peter turns down every request.
Wings to Fly uses the fact a character considers they failed such a test; Lucreiza Noin had a chance to prevent the Libradrop attempt by shooting Zechs Merquise, who she loves, in the back at one point. She never even thought to raise a weapon. Noin considers this the greatest shame of her life, though no one knows she had the chance. Noin eventually confesses to her wingman in the apparent hope she'll be judged harshly.
In I Owe You Every Joy of Love, Alya has been having a really rough month. Ladybug benched her alter ego Rena Rouge after she posted a manipulatively edited video on the Ladyblog; Marinette asked her to give her some space after an argument; she got grounded after inadvertently ignoring her family's attempts to call her and causing her sister to miss an important match, and her boyfriend has just suggested that they might need to take a break. Cue Hawkmoth attempting to akumatize her into Friend Zone. Alya manages to resist and reject the butterfly, refusing to let him tempt her into betraying Ladybug. She does so knowing full well that nobody else will know what she's done — if she had been akumatized, people naturally would have found out as she rampaged, but because she resisted, only she and Hawkmoth are aware of what happened.
Sins of the Past: Before she enacts her Wounded Gazelle Gambit, Lila privately offers Marinette the opportunity to spare herself by backing down and admitting defeat. Marinette refuses, sticking to her principles... and because of this, winds up losing everything.
Endeavor in Midoriya Tenko manages to unintentionally net himself some good publicity after some paparazzi spying on him find him admonishing the concepts of "heroic" and "villainous" quirks and encouraging Midoriya to be a hero despite his quirk being considered "villainous".
Deconstructed in the Sleeper Hit AU. Aizawa expels Izuku from U.A. on the very first day, fudging the results of his Quirk Assessment Test so that he can boot out the Quirkless kid and keep on the girl with Invisibility while creating a slot for his protégé to eventually enter his class. He then secretly issues an anonymous endorsement to help him get into another Hero Course. When he reveals this to Shinsou, he's less than impressed, declaring that it doesn't balance out the harm caused by his public actions. In fact, it makes them worse: he didn't truly believe that Midoriya lacked potential, but that didn't stop him from kicking him out for his own selfish reasons and presenting it as though he just wasn't good enough for U.A. In light of this, his secret act of compassion just underscores his hypocrisy, coming off more as something he used to soothe his guilty conscience.
The Best Night Ever has Prince Blueblood, stuck in a "Groundhog Day" Loop on the day of the Grand Galloping Gala, work very hard at shedding his Prince Charmless qualities and go full-out to make the Gala as good as it can be in order to escape. Due to the huge amounts of loops (numbering in the hundreds if not thousands) as well as the desperate attempts of becoming free (he even attempted a dark spell to create an unquenchable fire at the cost of his soul) before he attempts to improve, he is clearly reaching a limit. While his latest attempt seemingly goes off right, it fails because he's trying too hard, and all of it comes across as artificial. As he goes out into the palace sculpture garden, stands at the foot of Discord's statue, and seriously considers setting him free in exchange for finally stopping his nightmare. After a long moment of contemplation, Blueblood finally decides he can't do it, and walks away to try one more time. He finally ends up succeeding and completing his transformation from Prince Charmless to The Wise Prince.
In the Pony POV Series, it's shown in the Origins arc that when Discord was reincarnated on Earth following the Alicorn/Draconnequi War, Galaxia attempted to smother him in his crib... and couldn't bring herself to do it, even knowing what he would become if he regained his memories. She lived to regret this.
In Background Pony, Lyra ambushes Straight Edge, the alcoholic, abusive father of Snips, and breaks his legs, knowing that she can get away with anything thanks to her curse, which edits her out of the memory of anyone she interacts with after a short period of time. However, she stops short of breaking his horn because of this trope, and even transports him to the hospital once he's forgotten about the attack.
Lyra's decision in the penultimate chapter also qualifies. The only way she can remove her curse is to play the last elegy of the Nocturne of the Firmaments, and, in the process, rewind time to the moment she was cursed and erase all the good she had achieved, up to and including the crucial role she played in defeating Discord. No one, herself included, would ever know if she took this option, but Lyra decides against it and returns to Ponyville to live out her life as an Unperson with a fractured memory.
A Diplomatic Visit: In chapter 7 of the second sequel, Diplomacy Through Schooling, Neighsay is offered a chance to join Tirek as a loyal follower, and revenge on Twilight for causing all this misfortune to happen to him. He considers for just a second before refusing.
The Pieces Lie Where They Fell: As revealed in chapter 26 of the sequel, Picking Up the Pieces, Prince Blueblood was given the chance to end the line of changeling queens... but refused to do so, since it would have involved murdering an infant.
In Peggy Sue fanfic The Second Try, nobody knew that Shinji and Asuka were time-travellers. They could have let everything happen again, not try to change anything, or quit piloting to spare themselves their worst ordeals, and nobody would ever know that they had left the world dying. Still they chose fighting and trying to save the world.
In chapter 23, Nyarlathotep tried to talk all Children into joining him while they slept. All refused him.
"Look, my offer stands, up until the bitter end, okay? So when you're face down in the dirt and your friends are all dying around you, keep me in mind. Just say the word and you'll be saved, your friends will be saved, your sister and Kensuke will be saved, and everything will be alright." "You're still not taking my soul."
The Children and Misato could have lived forever in the False Utopia created by Gendo and Yui, even though that world was being steadily corrupted by the power used to create it, and no one would ever know it. However they chose to fight and restore the real world.
In the first scene of Neon Genesis Evangelion: Genocide, starts out similarly to End of Evangelion with Shinji visiting a comatose Asuka in NERV's infirmary. He accidentally gets Asuka's gown unbuttoned, and he realizes he can do to her whatever he wanted and no one would ever find out. However, signalling the beginning of the divergent storyline, he catches himself and instead quickly covers her up before leaving the room, feeling profusely disgusted with himself.
Also, in the main storyline, Ash catches a Gyarados on Misty's behalf when he could have easily caught it for himself (although in this case he was also aided by his 'knowledge' that this was the Gyarados Misty had in the original timeline which had a past history with her).
In Atlas Arc, Jaune's initiation into Atlas Academy involves being dropped off in the middle of nowhere while wearing a token that will allow Atlas personnel to view his progress once he returns. While traveling, he comes across a lone Huntsman who is in desperate need of reinforcements but is unable to call it in due to the area's reception. Without hesitation, Jaune destroys his token, which prompts Atlas to send in Huntsmen to investigate and save them. While destroying the token meant that Jaune failed his intitiation, Ironwood decides to make an exception for him because it was an emergency.
In Midnight Divergence, Cinder sees her Stepsister (who had abused her and than tried to apologize) being pursued by a beowolf. Despite hating her and realizing that no one would ever know if she let her die, Cinder ultimately saves her stepsister because that's what a huntress does.
In the Concerning Us endgame Janine finally faces the man who ordered the assassination of her aunt, instigated then covered up the incident leading to her brother's possession and death, tried to kill her girlfriend and has been the source of much misery. She has the choice to kill him herself or bring him to justice. She admits that killing him is a tempting option, but she will refrain from doing so to give justice to the other victims and because her dead friends believed in her to do the right thing.
In Purple Days, Joffrey Baratheon, trapped in a "Groundhog Day" Loop, is led by circumstances into a high-ranking position at the Dawn Army in Yi-Ti. Eventually, the Zombie Apocalypse spilling from Westeros reaches Yi-Ti. With the White Walkers and wights laying siege to the Dawn Fortress, a heavily injured Joff reflects that he's likely to die for real if the Walkers kill him. Briefly, he considers running away or killing himself to reset the loop, sending him back to his pampered lifestyle at King's Landing. However, he ultimately decides doing so would mean abandoning his men and proving he still was the same idiot coward he started as in canon. He stands his ground and dies with the rest of the Dawn Army, and while the return trip is extremely bumpy even for his standards, Joff manages to return for another try. And another. And as many as it takes to save the world.
In the fic "To the Journey", after Voyager returns to the Alpha Quadrant, Tom is disgusted that most of the people coming to see him are his former 'friends' who abandoned him after Caldik Prime; while Tom was willing to forgive his father's past treatment of him because Admiral Paris accepted that he hurt Tom and wants to apologise, everyone else showed their true colours when they abandoned Tom after the accident and are only here now expecting everything to be as it was before.
In The Prodigal Daughter, while Marla Gilmore feels that she failed this test when she not only went along with what happened on the Equinox but also rebuilt the enhanced warp drive for Section 31, Janeway counters with her new understanding that events on the Equinox were exceptional circumstances and chooses to focus on how long Marla held out against torture specifically designed to break her in the second case.
In Don't Let Go, Jack goes back to the night of Ianto's death with a syringe of nanogenes specifically programmed to cure the poison used by the 456 and bring Ianto back to life. However, when Jack witnesses a man sobbing over the body of his pregnant wife, even though he could easily cure Ianto and never tell him what happened, Jack sacrifices the nanogenes to bring the mother and unborn child back to life instead.
In The Shattering of Oz, a very literal example of this occurs for Dorothy and Elphaba when Elphaba briefly talks to Dorothy before she takes part in the Nome King's 'game'; as they are talking in a darkened corridor and Elphaba doesn't introduce herself, both parties give their honest feelings about the current situation, with Dorothy's genuine grief at her perceived role in the deaths of the Witches and Elphaba offering unnecessary sympathy and condolences for Dorothy's trauma helping both parties accept that they no longer have to be enemies.