Because you like Bill S. Preston in Bill & Ted's Excellent Adventure

Peter Venkman's "research" projects are designed to get undergraduate students to sleep with him. Though it turns out he can bust ghosts. See them in Ghostbusters.

Bree Van De Kamp likes her whiskey's neat, her napkins pressed, and her guns loaded. See them in Desperate Housewives.

A formerly righteous wizard, Saruman has been corrupted by the forces of evil. See them in The Lord of the Rings.

Sam Weir lives for the simple things in life: watching Saturday Night Live and reading comic books. See them in Freaks and Geeks.

Basil Hallward is dominated, soul, brain, and power by Dorian. See them in Dorian Gray.

Jenny Flint is a devoted wife and daring crime fighter, which is pretty unconventional for a Victorian maid. See them in Doctor Who.

Claire Standish is a popular, perfect princess who's deeper than she seems. See them in The Breakfast Club.

Driven by obsession and anxiety, Monk bravely overcomes, or at least battles, his fears to help the world. See them in Monk.

A karate master/rocket scientist/squirrel, Sandy Cheeks is the only one who can clean up the other resident's messes in Bikini Bottom. See them in SpongeBob SquarePants.