Because you like Einar Wegener/Lili Elbe in The Danish Girl
Gollum is slimy and seething with hatred, the last person you would want to meet in a dark cave. See them in The Lord of the Rings.
Lyra Belacqua is prone to getting in trouble, but she's also clever enough to get out of it. Most of the time. See them in The Golden Compass.
Tiffany Doggett is usually a nice, good Christian. Just don't get her riled up! See them in Orange Is The New Black.
A responsible kid, Hugo Cabret is still capable of flights of fancy. See them in Hugo.
V is a violent anarchist with literally nothing left to lose. But, he might have a point. See them in V for Vendetta.
If you hang out with Bender in cool dive bars in 31st century New York, make sure you're on his "Do Not Kill" list. See them in Futurama.
A Vietnam vet, Travis Bickle spends his days driving his taxi and watching porn flicks. See them in Taxi Driver.
Clementine Kruczynski thinks that too many guys think she's a concept, or she completes them, or she's gonna make them alive. See them in Eternal Sunshine of the Spotless Mind.
Introspective Theodore Twombly would rather observe life than participate in it. See them in Her.
Lux Lisbon's flirtatious manner attracts a lot of male attention. She relishes the power that her sexuality grants her. See them in The Virgin Suicides.
Ezio Auditore Da Firenze is a little short-tempered, a lot fun-loving. See them in Assassin's Creed Series.