Because you like Professor Hershel Layton in Professor Layton
Maurice Moss is a dedicated IT guy who even talks like a computer. See them in The IT Crowd.
Columbus can't trust anyone. The first girl he let into his life tried to eat him. See them in Zombieland .
Catherine Linton was once spontaneous and rowdy but ever since marrying the wealthy Edgar, she has morphed into a boiling pot of emotional outbursts. See them in Wuthering Heights.
With an abundant supply of alcohol, nice restaurants, and free will, Crowley is a demon who is thoroughly enjoying his time on Earth. See them in Good Omens: The Nice and Accurate Prophecies of Agnes Nutter, Witch.
James Wilson is a compassionate doctor who willingly plays the sidekick. See them in House M.D..
Lady Macbeth takes being a powerful woman to a whole other level. See them in Macbeth.
Don't worry about this forensic scientist offing you unless you're a serial killer yourself. (You're not, right? Just checking.) See them in Dexter.
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.
It's hard enough for Marta Cabrera to be part of a murder investigation, but when you can't lie? See them in Knives Out.