Because you like George Bailey in It's A Wonderful Life
Hanna Marin is a determined girl defined by her ability to transform herself. See them in Pretty Little Liars.
With the ocean breeze behind him and the open seas ahead of him, Jack Dawson feels as if he is king of the world. See them in Titanic.
Emmet Brickowski is so upbeat it's not even human. Everything is AWESOME! See them in The Lego Movie.
Jenko was top dog in high school. Now he's bottom of the pack in the police academy. See them in 21 Jump Street.
Courteous, dangerous, and powerful, Kaname Kuran controls an entire court of vampires. Very, very pretty vampires. See them in Vampire Knight.
Ciel Phantomhive is a haughty teenage nobleman who doesn't suffer fools gladly. See them in Black Butler.
Dominic Toretto lives his life "a quarter mile at a time", and he burns through those miles faster than anyone. See them in The Fast and the Furious.
Tyler Gage is going to have to step up soon on the dance floor. Otherwise, it's back to janitorial work. See them in Step Up.
Konata Izumi has a live-now, worry-later view of the world. See them in Lucky Star.
Severus Snape is a misanthropic potions teacher with a vindictive streak. See them in Harry Potter Series.
Sheldon Cooper is brilliant in every way except, well, interacting with any human being. See them in The Big Bang Theory.