"A family walks into a talent agent's office..." So begins "The Aristocrats," a joke kept mostly secret by stand-up comedians for decades. An intentionally "bad" joke, the laughs in The Aristocrats aren't in the punch-line (one of the only elements that's the same every time), but in the set-up, made unique by each comedian who tells it in an attempt to fashion the world's dirtiest joke. The cat was finally let out of the bag by Penn Jillette and Paul Provenza, the seasoned funnymen who gathered together a hundred people to tell a hundred different renditions of the bit. Among those presenting their personal take on The Aristocrats in this film of the same name are Jason Alexander, Robin Williams, Gilbert Gottfried, Jon Stewart, Emo Philips, and Chris Rock. The Aristocrats premiered at the 2005 Sundance Film Festival.