The main focus of the play and movie Short Eyes, in which a child molester is sent to prison. It doesn't end well for him.
Urinetown: "If there's one thing I've learned in my many years of enforcing the laws of this city, it's that the journey down to Urinetown offers no surprises. Not even from the very toughest among us. On that journey, expect only... the expected."
The Pirate King in The Pirates of Penzance—who commands a pirate band that refuses to rob orphans or to disobey an order of Queen Victoria—makes this salient point:
But many a king on a first-class throne, If he wants to call his crown his own, Must manage somehow to get through More dirty work than ever I do...
Richard III: Buckingham is a-okay carrying out Richard's orders until he hints that he'd like the Little Princes offed, rather ironically as he's the most likely suspect for having done the deed in real life.
The pickpocket is willing to be one of the one hundred thugs that will punish an impertinent poet; later, he tries to steal Christian but is caught by him, and he was willing to betray the thugs and denounce the plan in exchange for his freedom, but when Christian asks for the name of the perpetrator, he doesn’t want to talk and lampshades this trope:
The pickpocket: I may not say—a secret... Christian(shrugging his shoulders): Oh! The pickpocket(with great dignity): ...Of the profession.
Cyrano maybe is not evil, but he is definitely a Jerk Ass and he is proud of it, so when the the buffet girl offers him some food he is eager to lampshade this:
De Guiche sends a hundred men against a poet and stages a Last Stand after one too many humiliations from the Gascons, but then he declares the reason for his Heel–Face Turn:
De Guiche: I leave no woman in peril.
In Molière's Don Juan, while Juan is is amoral and unempathetic to others, in one scene, he intervenes to save the life of a nobleman who was attacked by bandits and grossly outnumbered. This works to Juan's favor, as the man he rescued turns out to have been the brother of one of Juan's abandoned conquests, which makes him become conflicted about his task of killing Juan. Additionally, Moliere had strong opinions about contemporary medical practice and how it was populated by a bunch of quacks and charlatans, and Juan echoes the author's opinions on this issue.
In Arsenic and Old Lace, the aunts are greatly offended when their nephew tells them to lie about killing various men. They may be murderers, but they would never "stoop to telling a fib!"
Differing greatly from his portrayal in the book, Fagin from Oliver! is far more Affably Evil and is increasingly horrified by Bill Sykes's brutality. It's best summed up in his song Reviewing the Situation:
Fagin: A man's got a heart, hasn't he? Joking apart, hasn't he? And though I'd be the first one to say that I wasn't a saint, I'm finding it hard to be really as black as they paint.
Fagin: I don't want nobody hurt for me, nor made to do the dirt for me. This rotten life is not for me, it's getting far too hot for me...
In Inherit the Wind: Matthew Brady may be an anti-intellectual religious opportunist persecuting a free-thinking teacher, but when a hateful pastor curses the teacher at a prayer meeting and condemns his own daughter for defending him, Brady publicly tells the Pastor to back off from his tirade.
Les Misérables. When the Thenardiers ask Valjean if his intentions are "correct", regarding his plan to take Cosette away from them. In all likelihood, they were just haggling for more payoff money, but there's always the chance they were genuinely concerned. For all their mistreatment of Cosette, it's never once implied that they're molesting her or allowing others to.
Though given that after Valjean offers them 1500 francs for Cosette, they never again worry about his "intentions," that somewhat undercuts the argument that they were honestly concerned for her.
Even way back in Doctor Faustus, the Noble Demon Mephistopheles repeatedly tries to get Faustus to reconsider eternal damnation for temporary power. Faustus is just too egomanical to see reason.
Mad Padraic, the titular character from The Lieutenant of Inishmore, is a strange subversion. He is first introduced torturing a drug dealer who sells drugs to children. The subversion occurs when it turns out that the drugs he sells are only marijuana, the children are students at the local technical university, and that what Padraic is mad about is not him selling drugs to children, but not restricting his sales to Protestant children.
A more straight example is Padraic's past as a member of first the IRA, which he then left to join a splinter group (the INLA) of those whose methods were too extreme for the IRA, only to leave THAT group to form his own one-man splinter-of-a-splinter group because he was too extreme for the INLA too.
Brendan, one of the INLA members, is completely jaded when it comes to drug-dealing, arson, and terrorism, but recoils in horror when he finds out his compatriots have killed a cat.
The play could be considered a deconstruction of the concept. It is quite clear that the author thinks that being unwilling to hurt a cat when you have repeatedly and without remorse killed and tortured people does not mean you have morals, it just means you're a hypocrite on top of being a psychopath.
The British Black Comedy piece Great Britain is mostly comprised of morally ambiguous characters, but they mostly have some limits. Almost all of them are due to Paige Britain becoming more vile and ruthless.
Assistant Commissioner Donald Doyle Davison may be something of a Dirty Cop, but he's not a racist, and he encourages a racist officer to go to a course on tolerance. More seriously, he's horrified to find out that his cooperation with Free Press resulted in the arrest and subsequent murder of the innocent Kieron, leading to his cutting off all links with Paige and subsequent resignation.
The staff of "Free Press" generally have no problem exposing the dirty secrets of celebrities, viewing it as "just business". They draw the line at two things, however- they are outraged by Paige letting Scarlett starve to death so that they can have exclusive rights to her death story, and the news that their sting operation went horribly wrong causes at least one of them to try and resign.
In a tragically misguided case of this trope, some inmates at Broadmoor murder Kieron Mills, believing him to have sold his kids to a paedophile. In reality, he was completely innocent and only vindicated posthumously.