Because you like Leonard Hofstadter in The Big Bang Theory

Told her son will one day save the world, Sarah Connor dedicates her life to training him to do just that. See them in The Terminator.

Clank is the quintessential rational, intelligent robot sidekick. See them in Ratchet & Clank.

Daring on a bike but haunted in his personal life, even Johnny Blaze isn't fast enough to outride his past. See them in Ghost Rider.

Yukiteru is a reclusive observer who would rather watch life go by than participate in it. See them in The Future Diary.

Amber Holt is perpetually caught between forging her own path and stumbling around in the dark. See them in Parenthood.

Captain Spock is on a five-year mission exploring the final frontier and boldly going where no man has gone before. See them in Star Trek.

A speed-loving daredevil who lives on the edge, Sonic is as brave as he is cocky. See them in Sonic the Hedgehog.

Raphael is a short-fused hothead who loves a good fight and some tasty pizza. See them in Teenage Mutant Ninja Turtles.

Moving is hard for Coraline Jones; accidentally moving to a creepy mirror world just makes it harder. See them in Coraline.

Yuki Cross is a cheerful, funny, bold young woman with hidden insecurities. See them in Vampire Knight.

People think that because Tris is small, or a girl, or a Stiff, she can't possibly be cruel. But they're wrong. See them in Divergent.

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