Because you like Cal Trask in East of Eden
R2-D2 has been in the galaxy saving business for decades. Not bad for somebody whose vocabulary is limited to "beep-boop." See them in Star Wars Series.
A bumbling hobbit, Bilbo Baggins is becoming a part of something much larger than himself as he embarks on a quest. See them in The Hobbit: An Unexpected Journey.
Running away from murderous aliens has turned into an interstellar chase for Jupiter Jones. See them in Jupiter Ascending.
A suave demon, Crowley grants humans their wishes in exchange for their soul, only to find loopholes that benefit him. See them in Supernatural.
There is never a dull moment with Jim Moriarty: expect booze and sing alongs in between all of the homicide. See them in Sherlock.
If Lisbeth Salander can hurt a bastard who deserves it by digging up stuff about him, she feels good. See them in The Girl with the Dragon Tattoo.
Toph is a tenacious earthbender full of spirit and spunk and hates when people try to baby her because she's blind. See them in Avatar: The Last Airbender.
Selfishly taking her father’s place to fight in the Imperial Army, Hua Mulan risks treason if they find out she isn’t who she says she is. See them in Mulan.
Artemis Fowl understands the way of the world. If he wins, he's a prodigy. If he loses, then he's crazy. That is how history is written. See them in Artemis Fowl.