As seen on: Family Matters (ABC)
Portrayed by: Jaleel White

Urkel builds a machine that turns him into Laura Winslow's dream man: Jaleel White. That was the transformation, wasn't it?

We're not totally sure what made Stefan so cool. He only sounded cool because the Urkel voice wasn't burrowing into your ear drums. In that comparison, Stefan probably sounded like Sinatra. What else? He wore baggy blazers (it was the '90s, after all) and, um, he played the piano in one episode. Compared to his alter-ego Steve, Stefan's dullness must have been downright charming.