Mystery Science Theater 3000 has made me laugh for about a decade and a half now; I actually went to their 1996 convention in Minneapolis. One might well wonder, what made them laugh?
During the taping of the final episode, in which the movie Diabolik got riffed on, the editors sprung a montage of previous bad movie moments on the unsuspecting Mike, Crow, and Tom Servo.
You don't have to have seen the movies to enjoy the reactions (though this blog's readers might remember the Gumby episode). My favorite clip is at 2:35-2:39; I'm guessing it's Mike's favorite too, judging from his barely audible "Oh my gosh" and his contiuing laughter afterward.