Because you like Marv in Sin City
Dolores Umbridge keeps her villainy hidden (albeit poorly) behind a sheen of sugary pink politeness. See them in Harry Potter Series.
Christine Palmer is a great surgeon and an even better friend. See them in Marvel Cinematic Universe.
Juno MacGuff is hoping sarcasm will get her through the stress of teenage life. And also, teenage pregnancy. See them in Juno.
Even with the world on the line, Bayonetta is an Umbra Witch who maintains a biting sense of humor. See them in Bayonetta.
Betty Cooper seems like a sweet girl, but she also has a dark side and can go beyond what's safe or sane. See them in Archie Comics.
Mark Zuckerberg has achieved everything he's ever wanted, and he's proving to the world how brilliant he is. But happiness eludes him. See them in The Social Network.
Sookie Stackhouse is a waitress who can read minds and break hearts. See them in True Blood.
His name is Inigo Montoya and whoever killed his father should be prepared to die. See them in The Princess Bride.
There can be no doubt that Ben Linus is a huge liar. But one man's lies are another man's necessary steps to protect his people. See them in Lost.
Keeping your cool is just as useful in the underworld as in war, and Michael Corleone is stone-cold. See them in The Godfather.