Because you like Catherine Tramell in Basic Instinct
Optimus Prime is a shapeshifting sentient robot leading a team of robots to stop evil from taking over. See them in Transformers.
There is never a dull moment with Jim Moriarty: expect booze and sing alongs in between all of the homicide. See them in Sherlock.
The poster child for relentless cheer and resilience, Kimmy Schmidt may be an abuse survivor but she's also a lover of dancing and karaoke, candy, and dolphins. See them in Unbreakable Kimmy Schmidt.
Stuck somewhere between life and death, Talion is motivated by one thing only: vengeance. See them in Middle-earth: Shadow of Mordor.
Vanellope von Schweetz is princess of the Sugar Rush game who could care less about being royal. See them in Wreck it Ralph.
Christian Grey is just as controlling in the bedroom as the boardroom. See them in Fifty Shades of Grey.
Fiery, intelligent, and opinionated, Jo March rebels against the restrictions of her era. See them in Little Women.
Cynicism is his armor and words are his weapons, but what Tyrion Lannister would really like is some nice wine. See them in Game of Thrones.
Beautiful and artistic, Aria Montgomery follows her own path. See them in Pretty Little Liars.
Buttercup is a farm girl turned princess who'd do anything to have her old life back. See them in The Princess Bride.
Wolverine is a hot-blooded Canadian with an adamantium skeleton who's the best at what he does. See them in X-Men Series.