The Simpsons has been using guest stars since the very first season. Some have returned on several occasions, sometimes as different characters (Albert Brooks), sometimes as the same character (Kelsey Grammer), and sometimes as both (Jon Lovitz). By my calculations there have been exactly twelve thousand guest stars on the show so far, so obviously a list of just five is going to be lacking just a tad. Nevertheless, these are five guest stars who stick out in my mind. Got some more? That's what the comments are for. Here we go:

Albert Brooks: Brooks first appeared in season one as Jacques, the man with the fake French accent who tries to woo Marge away from Homer with his knowledge of bowling and women. He later appeared as Hank Scorpio, a rather paradoxical character who is both very friendly and yet extremely evil. I think my favorite Brooks episode, however, was the episode "The Heartbroke Kid" when he played Tab Spangler, a ticking time bomb of a coach who tries to coerce Bart back to health after Bart gains weight and suffers a heart attack. "Every sign is wrong!" He'll also be appearing in the Simpsons movie, which is very cool.