Because you like Clank in Ratchet & Clank
A vampire hunter, Integra Hellsing doesn't tolerate failure, least of all her own. See them in Hellsing.
N'Jadaka is a righteous man with a violent agenda. See them in Marvel Cinematic Universe.
A kind and funny valedictorian, Gwen Stacy likes to make out with Spider-man when her homework's done. See them in Marvel Cinematic Universe.
Sydney Bristow is a kick-ass double agent on a mission for revenge. See them in Alias.
Just call Jeff Lebowski The Dude. Or His Dudeness, Duder, or El Duderino if you're not into that whole brevity thing. See them in The Big Lebowski.
Marty McFly is a skateboarder, aspiring rock star, and reluctant time-traveler. See them in Back to the Future.
Edward Elric has a quick mind along with a quick temper. See them in Fullmetal Alchemist.
Jim Stark is a teen torn apart by what the world asks of him. See them in Rebel Without A Cause.
Though he has a brilliant mind for mathematics, Christopher has a much harder time processing the rest of the world. See them in The Curious Incident of the Dog in the Night-Time.