Jack: How do you know Im not?
Laurel: I know I know because
Jack: How do you know?!
Laurel: I know, because I never loved him the way that I love you.
A person is replaced at some point in the plot by an imposter, but their original friends prefer the imposter.
It turns out that the original, while being the real one, is a lousy person. The fake, on the other hand, turns out to be better in general. They are kind to puppies, they actually love the wife instead of treating her as a sex object, and they are a good person in general. When the original comes back, nobody wants them around.
- A Certain Magical Index has a very strange example: after losing his memories at the end of the first book, Touma decides to hide what happened and spends the rest of the series impersonating himself. With limited information to go on, he becomes convinced that the pre-amnesia Touma was some kind of Crazy Awesome All-Loving Hero, and that he'll need to act that way in order to avoid suspicion. In particular he has no idea how long Index has been living with him, and assumes that she's a long-time friend rather than someone he just met.
- In JoJo's Bizarre Adventure: Diamond is Unbreakable, the villain Kira hides from the heroes by stealing a random man's face and identity without anyone realizing (except the man's son). As it turns out, though, Kira is a much better husband than the original and makes his "wife" fall in love with him all over again, saving their crumbling marriage in the process. Of course the only reason for that is that Kira has to act normal and avoid enacting his hobby (killing pretty young women while keeping their severed hands as company) for a while.
- Batman: After Batman is presumed dead following Final Crisis, Dick Grayson takes his predecessors mantle, but makes it clear that none of Batman's enemies can ever think that he's died. They must believe that Batman is unkillable. As Dick settles into the role, the police, several superheroes and even some villains have found that Batman has become a lot more pleasant to deal with, as Grayson is much more of a Nice Guy, and has much less mental baggage.
- The premise of Superior Spider-Man involves Otto Octavius stealing Peter Parker's body and applying his criminal mind to Parker's various problems. Without Parker's moral code to weigh him down, Octavius manages to temporarily end Spider-Man's Hero with Bad Publicity reputation and makes Peter Parker a rich man by patenting his various inventions. On the other hand, he quickly alienates all of Spider-Man and Peter Parker's friends because he's a total asshole.
- In Dave an Identical Stranger is brought in to impersonate the President who has fallen into a coma. Over the course of the story the First Lady realizes that she likes the impersonator a lot more than she likes her husband. Not to mention the impersonator has a moral spine the real president lacked.
- In The Man in the Iron Mask, the Three Musketeers scheme to replace the Royal Brat Louis XIV with his secret polar-opposite twin Philippe, who was locked away with his face masked to hide the family resemblance. Ultimately, it works: Louis takes Philippe's place in the Bastille, while Philippe takes Louis' identity and becomes one of France's greatest kings.
- In Sommersby, the titular character went off to the Civil War, and was supposedly killed. Someone claiming to be Sommersby appears at his village, and starts helping them recover from the war's effects. By all accounts he wasn't a pleasant man before, but now is kind and helpful—so much so that his wife Laurel seems pretty convinced it isn't the same man, but welcomes him in because of his change in demeanor. This movie inspired the plot of The Simpsons episode "The Principal And The Pauper" (see below in Western Animation).
- White Chicks, two (black male) cops take the place of the title characters. Their disguise is horrible, but their personalities are much sweeter, so the girls accept them even after the disguise is revealed.
- A Clockwork Orange: When Alex is released, he returns to his parents' home only to find they've taken in a lodger, a young man they treat like the good son Alex never was.
- Marco is horrified to discover that while Erek (an android who can use a hologram to look like anyone else, and in this case was covering for Marco's absence during a mission in the Arctic) was impersonating him, he cleaned his room, something Marco quickly set about correcting (to his dad's chagrin).
- Subverted in a story where Rachel suffers Literal Split Personality, with Mean!Rachel having all the aggresiveness and Nice!Rachel all the... fashion sense? However, it soon turns out Nice!Rachel is a spineless wimp who bursts into tears at a moment's notice, so the team quickly look for a way to bring back the real Rachel.
- In Ann Leckie's short story "Marsh Gods", Voud's brother Irris is murdered near a dormant god, so the god possesses the corpse and takes over the brother's life. His family realize almost immediately because the "brother" is no longer selfish and indolent, and agree to protect his secret in exchange for the god's protection of their village.
He handed her a bronze knife. It was small and its plain haft was dented, but it was a real metal knife and it was hers.That was when she knew for certain that her brother was dead. Irris would never have thought to buy her something she wanted so much.
- The Lightbringer Series has Gavin Guile, the main character who is the heroic Prism, able to master all the colors of the spectrum and use them without breaking his eyes (the way magic works in the series is creepy). Only, we learn midway through the book that the prisoner is Gavin and the one outside is his brother Dazen. As a person, Dazen was better even before impersonating him. For example, Gavin failed a test (that everyone fails) while Dazen was the only one in recent history to pass, Dazen is a superchromat (allowing him to fine-tune yellow and see more shades of color) while Gavin wasn't, Gavin was an Abhorrent Admirer. To top it off, Gavin is described as exceedingly vain and haughty, while Dazen is basically The Paragon in terms of how he leads.
- In "The Tercentenary Incident" by Isaac Asimov, the President is apparently killed on the 300th Independence Day. However, right after, he reappears and explains it was a robotic body double which was destroyed. However, due to how much the President improved from his former cynical vote-grabber self, it is suspected the robot double is the one to have assassinated the human for the good of the nation.
- In S.P. Sontow's novel Valentine, the focus is on a reality TV show auditioning child-stars re the best possible imitation of the vanished teen idol Timmy Valentine - the intention is to keep the money-making machine going by marketing the imitations. The winner, Angel Blake, is an uncanny absolute dead ringer for the vanished teen idol. he is even described as "Timmy Valentine plus". The original Timmy returns and the secret of his mesmerising charisma is revealed - he is a two thousand year old vampire.
- In the original The Shadow novels, The Shadow is actually secret agent Kent Allard who's impersonating millionaire playboy Lamont Cranston while the latter lives on a permanent vacation in Europe with a nice monthly stipend. This works out because Allard is both more moral than Cranston and also better at managing the latter's finances.
- The Filipino Telenovela titled "Impostora". Two versions have been made, each having different plots and characters, but the premise is the same. Both versions have a premise where the protagonist gets plastic surgery to look like the woman who found her, and the woman tells the impostor to stay with her man while she fools around with other boys. The impostor agreed, and it went horribly right as the impostor was a better, kinder person to the man and kids than her real counterpart, who was a total bitch. The 2007 version has the protagonist looking for her long lost twin only to find a total stranger who looks like her, while the 2017 version has the protagonist being mocked for her ugliness and runs away after accidentally hitting her heckler.
- The Mexican Telenovela "La Usurpadora" is about two women who are identical and the rich bitchy woman trades places with the impostor just so that she could have fun. The impostor is much well-recieved by the rich bitch's family, and the rich bitch took notice and want to have it back at all costs.
- The Riches stars a family of Irish Travellers who find Doug and Cherien Rich dead in a car crash, then steal their identities and move into their home in Stepford Suburbia. When they meet Cherien's elderly mother, she sees through them immediately despite the new "Mrs. Rich"'s best efforts to play the dutiful daughter, although the nurses write it off as dementia. The mother eventually explains that she knew because "[Cherien] was a bitch" and is happy to smoke pot and have a drink with her new "family".
- In Dishonored 2, Corvo or Emily can secretly replace the corrupt Duke Luca Abele of Karnaca with his own body double as the non-lethal alternative to just assassinating him. On a Low Chaos playthrough, the impostor turns out to be a much better and capable ruler who turns the situation in the city for the better (though on High Chaos, he turns out just as corrupt as the original...).
- One quest in Fallout 4 revolves around The Institute Killing and Replacing a homesteader with a Synth. The original homesteader was a belligerent drunk who beat his wife and kids, and although they don't know the reason why, his kids will tell you that he suddenly became a lot nicer a short time ago.
- Tales of the Abyss:
- The original Luke Von Fabre was kidnapped and cloned to create another Luke. The original went on to become Ashe the Bloody, while the clone was returned to the original's place. After the (clone) Luke accidentally destroys an entire city, his team abandons him to join Ashe. When Luke resolves to atone for his mistakes and Ashe turns out to be a bitter Jerkass, the team rejoins Luke.
- There are multiple Dual Boss fights between Ashe and Luke. The first borders on Hopeless Boss Fight, but the player is required to win the final dual. Thus, Luke overcomes his original in sword-skill.
- In The Witcher 3: Wild Hunt, if Geralt kills the mob boss Cyprian Wiley, Dudu (a doppleganger) will take over his identity. Wily is a depraved Serial Killer who has no concept of Honor Among Thieves, while Dudu is a naturally non-violent individual, who disbands Wily's criminal empire and reinvests his assets in a legitimate trading company.
- Dan Vs.: In "Dan vs. Dan", a doppelganger forces Dan out of his own apartment and steals his identity. Real Dan is such a jerk and loner that it only takes Fake Dan a few days of volunteer community service to become the more popular, better-known Dan. The real Dan only has two friends who are willing to vouch for him—and the imposter even wins them over, just by being kinder and more polite than the real Dan.
- Duck Dodgers: "Detained Duck" has a Spot the Imposter moment where the Cadet has to determine which between the real Dodgers and an impostor named Drake Darkstar. Dodgers attempts to help out, but everything he lists are mean things he did to his cadet. In the end, Cadet knowingly declares the impostor as being the real one after feeling that he'll ultimately be this trope.
- The Simpsons: In "The Principal and the Pauper", Principal Seymour Skinner is revealed to be Armin Tamzarian, who had inadvertently taken the identity of the real Sergeant Seymour Skinner whom he served in the army with. Armin had actually visited Mrs Skinner, intending to inform her off her son's demise, however Mrs Skinner mistook him for her son and he went along with it. When the real Seymour Skinner returns and tries to reclaim his old life, Mrs Skinner is thoroughly annoyed by how disobedient and irresponsible he is. She opts to have Armin back as her son, reasoning he had actually been her son for longer (as the real Seymour had been absent from her life while serving in the army and captured by the enemy). The real Skinner is also given Armin's job as school principal, which no one thinks he's any good at. In the end the real Seymour is honorably farewelled from Springfield as a war hero (and tied to a train headed out of town), while Armin is allowed to stay and legally continue using the name "Seymour Skinner" while living with his mother.
- Spongebob Squarepants:
- In one episode, Plankton builds a Robot Me version of Mr. Krabs in order to try to take the Krabby Patty formula. In the process, SpongeBob makes him go through a very complicated process before it can be shared. The real Krabs comes back right before Plankton gets a copy of the formula, so SpongeBob gives them a test to Spot the Imposter. The questions he asks are so obscure that only Plankton knows them from just having review them all SpongeBob, causing SpongeBob to shoot Krabs with tartar sauce and throw him out. It's not until some minutes later (after the Krabs bot self-destructed due to SpongeBob's actions) that he realized that he kicked out the real Krabs.
- Parodied in the episode "Squid Wood", where customers at the Krusty Krab like Spongebob's Squidward puppet more than the real Squidward, to the point where the puppet replaces him as a cashier at the Krusty Krab and is given the $1 million clarinet performing contract Squidward wanted.
- In an early South Park episode, a good version of Cartman from a Mirror Universe comes to South Park, looking to escape from the evil Jerkass version of the gang in his dimension. Towards the end of the episode Stan and Kyle get ahold of a gun that can zap someone into the mirror universe and intend to use it on their Cartman, as they naturally prefer the alternate version to the one they know. Unfortunately for them, Cartman manages to start a Spot the Imposter scenario and then tricks them into sending the alternate version back to his original universe.
- In the Steven Universe episode "The New Lars", Steven accidentally possesses Lars' body. Steven takes it as a chance to get Lars to admit he loves Sadie, and along the way acts far nicer than Lars does usually (even though he was trying to blend in). Lars' parents and most of his friends are pleased, the exception being Sadie herself—and half of her dissatisfaction was suspecting the attitude change was just a trick. Lars did not take it well when he learned that almost everyone was happy that he was acting weird all day.
- In the Justice League episode "The Great Brain Robbery", Flash and Luthor get mind-swapped. Tala finds Flash!Luthor preferable to normal Luthor, since he's a nicer guy and is strongly implied to be a better lover.
- This may have happened during the Martin Guerre case in 16th-century France. The imposter Arnaud du Tilh successfully stole the identity of Martin Guerre for three years—even convincing Martin's wife and family that he was the real deal—before he was discovered, tried, and executed. Historian Natalie Zimon Davis has argued that the wife, Bertrande Guerre, must have known all along that Arnaud was an imposter—but went along with the deception because he was a better man and kinder husband than the real Martin. This interpretation has influenced adaptations of the story, like the 1982 film The Return of Martin Guerre and the musical Martin Guerre.