At my high school there were two movies the drama kid's declared as cult classics that everyone must see: The Rocky Horror Picture Show and Clue. There were others that people declared as school classics on their own, but those two were undoubtedly agreed upon by everyone. Lucky for me, Markos somehow stumbled upon it in Middle School and showed it at one of his parties.
The movies premise is the same as the board game it is based on. Six strangers wind up in a weird house for a dinner party for which they are given the aliases which we know them by. The only one's who aren't in the game (who play a big part in the movie) are Mr. Body and his workers (a butler, cook, and french maid). When the secret which ties them together is revealed (and others start popping up), people start dying. Sounds a lot like the game, huh? Wonder why...
Everyone in this is fantastic (and pretty dang famous, too) and although it is a mystery/crime movie, it is one of the funniest movies that came out of the 80's. It's just plain hilarious. Surprisingly, it didn't just rely on stupid humor either, but used some very subtle humor as well.
Although this movie didn't do so hot in theatres, it quickly became a college classic... probably because it's just cheaper to rent than go to the movies. And once it's rented, you can just show it to other friends. That's my theory on this one... but really, it deserves to be a cult classic. It's a solid flick.