Because you like Alex DeLarge in A Clockwork Orange
Ponyboy Curtis is a "Greaser" on the surface, but he's a sensitive poet underneath. See them in The Outsiders.
Severus Snape is a misanthropic potions teacher with a vindictive streak. See them in Harry Potter Series.
Donna Pinciotti is strong, independent, and empathetic. No one messes with her. See them in That '70s Show.
Driven, resentful, and ruthless, Mello is an emotional powder keg. It's only a matter of time before he explodes. See them in Death Note.
Obi-Wan Kenobi is a sage Jedi who doesn't need to say much to teach you a galaxy's worth of wisdom. See them in Star Wars Series.
Calling Alicia Florrick a "good wife" is damning this smart, capable, thoughtful woman with too-faint praise. See them in The Good Wife.
Arwen has to choose between a life of loneliness or love and inevitible death, both rather unfortunate options. See them in The Lord of the Rings.
The Genie is the perfect buddy, granting every wish we might have and keeping life good-spirited. See them in Aladdin.
Darcy Lewis is a razor-sharp scientist studying things that science can't explain. See them in Thor.
The party never really ends with Penny Lane, a rock-worshipping groupie who is refreshingly self-aware and free-spirited. See them in Almost Famous.
Phoenix Wright is an easygoing defense attorney who is rarely defensive. See them in Ace Attorney Series .