Because you like Alan Grant in Jurassic Park
Bella Swan thinks of it as her job to help her parents and protect her friends, even though it often ends up the other way around. See them in Twilight.
Tracy Turnblad's got rhythm, and she's determined to share her dance moves with the world. See them in Hairspray.
Usagi Tsukino may look like a lazy teen, but when Usagi conjures up her alter ego and calls her Sailor Scout team, no villain stands a chance. See them in Sailor Moon.
Alison DiLaurentis believes you're always better off with a really good lie. See them in Pretty Little Liars.
Jenko was top dog in high school. Now he's bottom of the pack in the police academy. See them in 21 Jump Street.
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.
A 100-plus-year-old who looks like a dreamy teenager, Edward Cullen warns girls to avoid him, which makes them want him even more. See them in Twilight.
Joey Tribbiani's true passions in life are acting, sandwiches, football, sex, and asking ladies, "how you doing?" See them in Friends.
A gentle alchemist who is soul-bound to a giant suit of armor, Alphonse Elric is growing into the responsibility handed to him. See them in Fullmetal Alchemist.
A natural leader, Clarke Griffin dispenses both justice and mercy, and she does it all while being selflessly humble. See them in The 100.
Years of being a social outcast have taken a toll, but Elphaba is willing to be wicked if it means she can do good. See them in Wicked .