Because you like Mia Wallace in Pulp Fiction
Yes, she's an "older" woman, but that just makes Mrs. Robinson sexier and more seductive. See them in The Graduate.
Django was once a slave. Now that he has a taste of freedom, he understandably wants a full meal. See them in Django Unchained.
Roger Kint is a nervous, weak, ham-handed criminal. We think. See them in The Usual Suspects.
A secret smoker, Margot Tenenbaum has plenty more secrets where that came from. See them in The Royal Tenenbaums.
Max Fischer is the President of every club who's fighting to save Latin at his school and kiss his teacher. See them in Rushmore.
Hayley Stark is a sarcastic 14-year-old with an unusual passion. See them in Hard Candy.
Marv is a brutish but principled thug who'd be right at home on an ancient battlefield. See them in Sin City.
A jealous woman is dangerous. A jealous assassin woman like Elle Driver is even more so. See them in Kill Bill vol. 1.
Though she can seamlessly flit between glamorous identities, Sydney Prosser is more vulnerable than she pretends to be. See them in American Hustle.
Ava may just be the perfect woman. So long as she can pass a Turing test. See them in Ex Machina.