Movies: PAUL PROVENZA: The Dirtiest Joke Ever Told--And Retold

It's the simplest, raunchiest, most notorious joke in the world. A man and his family walk into a talent agent's office. Agent says, I don't book family acts. Man says, Just let us show you. Wearily, the agent accedes. The man and his wife undress and perform every form of bizarre, outrageous sex act. The kids join in, possibly also Gramps and the dog. They finish in a literal pyramid of filth. Aghast and astonished, the agent asks, What do you call your act? The man, with a bright flourish, shouts out, "The Aristocrats!"

As Bart Simpson would say, that joke is funny for so many reasons. It's also all in the telling, so it plays on comics' need to earn approval through lurid pirouettes of a lunatic imagination. And having spent all its shock value in the setup, it offers a punch line of cheerful poignancy. This family will do anything to be in show biz.

But would you want to hear the joke told over and over, for 90 minutes, by scores of comics? The surprise is: yes. The Aristocrats smartly varies its pace, with iterations by the old (George Carlin), the female (Whoopi Goldberg), the pranksters (Penn and Teller) and the deeply weird (Andy Dick). Also wordlessly (by Billy the Mime), as a card trick (by Eric Mead) and as a cartoon (by the South Park guys). The result is a master class in comedy, in all its cruel, larkish, obsessive creativity.

Warning: the language is the foulest ever heard in a movie. So don't bring the kids. Unless they're part of the act. --R.C.