Because you like Rachel Jansen in Forgetting Sarah Marshall

Matt Flamhaff is not too concerned about being part of the popular crowd. Too bad his best friend is. See them in 13 Going on 30 .

The chronically bizarre Dwight Schrute is the world’s most dependable assistant to the regional manager. See them in The Office.

Rose Tyler may have not done too well in school, but she's certainly holding her own in space. See them in Doctor Who.

Frederick Frankenstein is an eccentric (O.K., maybe a little insane) professor who is excited to be delving into his family's past. See them in Young Frankenstein.

Irene Adler has to use both her brains and her body to survive. Luckily, she's usually the most brilliant person in the room. See them in Sherlock.

David Rossi may chase serial killers for a living, but he's more interested in what wine pairs well with tonight's parmigiana. See them in Criminal Minds.

It turns out the girl of your dreams just might have dreams of her own. See them in (500) Days of Summer.

Howard Wolowitz is an engineer whose serious mommy issues somehow haven't dimmed his confidence. See them in The Big Bang Theory.

Mac is a karate-chopping, beer-chugging schemer. See them in It's Always Sunny in Philadelphia .

Princess Fiona is a damsel who doesn't need saving, but she's cursed with an embarrassing secret. See them in Shrek.

Breaking bones and hearts, Callie Torres has figured out how to put the bones back together. But the hearts? Not so much. See them in Grey's Anatomy.