Because you like Harry Kim in Star Trek: Voyager

You won't like him when Bruce Banner is angry. See them in Marvel Cinematic Universe.

Leonard Hofstadter is the normal one among his scientist friends, though in fairness that's a low bar. See them in The Big Bang Theory.

Donna is boisterous and spunky traveller of the TARDIS, exploring worlds beyond the simple mundane enterprises of Earth. See them in Doctor Who.

Velma Dinkley is all about getting results, not taking credit. She is the unsung hero of Mystery Inc. See them in Scooby-Doo.

A born psychopath, don't expect Michael Myers to understand the difference between right and wrong. See them in Halloween.

It's a race against time to develop his theory of the origins of the Universe before Stephen Hawking's body and mind give out. See them in The Theory of Everything.

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.

Arwen has to choose between a life of loneliness or love and inevitible death, both rather unfortunate options. See them in The Lord of the Rings.

Mitchell Pritchett prefers to have a place for everything and everything in its place. See them in Modern Family.

Charles Boyle is the human equivalent of a puppy, only slightly less adorable. See them in Brooklyn Nine-Nine.

Princess Bubblegum is brilliant and determined, but can display a nasty temper. See them in Adventure Time.

Stefan Salvatore was the golden boy when he was alive. Can he keep it up as a vampire? See them in The Vampire Diaries.