Because you like Cady Heron in Mean Girls
Ezio Auditore Da Firenze is a little short-tempered, a lot fun-loving. See them in Assassin's Creed Series.
Whether he's fighting or flirting, Jace Wayland is all swagger. See them in City of Bones.
Charismatic, sociopathic, and dramatic, Charlie Bronson wants nothing more than to be famous. See them in Bronson.
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.
It's hard enough fighting a war. But it's worse for Commander Shepard, knowing no matter how hard you try, you can't save them all. See them in Mass Effect.
Rose Hathaway is a reckless, rebellious smartass who's training to be a royal vampire guardian. See them in Vampire Academy.
Arthur Dent is an incredibly normal man on an incredibly abnormal adventure. See them in The Hitchhiker's Guide to the Galaxy.
James T. Kirk is more than ready to face the final frontier. See them in Star Trek.
Jax Teller can be cool or vengeful, calm or wrathful, depending on the situation. See them in Sons of Anarchy.
Effortlessly sexy, calm, and collected, Eric Northman is equally at home ripping off heads and flirting with waitresses. See them in True Blood.
Jason Bourne is suffering amnesia, but considering what he's done as a CIA assassin, maybe that's for the best. See them in The Bourne Identity.