Because you like Doogie Howser in Doogie Howser, M.D.

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.

Jacob Black is the boy next door who's also the wolf next door. See them in Twilight.

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.

A natural leader, Clarke Griffin dispenses both justice and mercy, and she does it all while being selflessly humble. See them in The 100.

Alison DiLaurentis believes you're always better off with a really good lie. See them in Pretty Little Liars.

Gollum is slimy and seething with hatred, the last person you would want to meet in a dark cave. See them in The Lord of the Rings.

Fun and feisty on the outside, Meredith Grey is dark and twisty on the inside. See them in Grey's Anatomy.

A bookish know-it-all with a bossy streak, Hermione Granger always stands up for what she believes in. See them in Harry Potter Series.

Hiccup Haddock III may be the only Viking nerd in recorded history. See them in How to Train Your Dragon.

John Watson is haunted by his past (who isn't) but he's starting to branch out with some help from a world class detective. See them in Sherlock.

A benevolent madman with a blue box, The Doctor is traveling through time and space to heal the wounds of the universe. See them in Doctor Who.

Chandler Bings keeps his friends on their toes with his cutting wit, all the while trying to discover his own place in life. Could he BE any funnier? See them in Friends.