Okay, I am interpreting "bad" as in stupid or completely moronic, naughty or socially incorrect. So I would say the movie "Strange Brew" which falls into all three categories. This movie can only be watched when completely wasted, so for me...once every couple of years. The next movie would be "Bad Santa" which is horrible and offensive but I secretly laugh at. Being the only liberal on the military base that I live on, I showed it on Christmas Eve to a bunch of Conservative friends....the shock factor was worth it! I also love "Fast Times at Ridgemont High"....completely stupid but always end up watching the whole thing if I am flipping through the channels and it is on.
Kathi