Psycho
Alfred Hitchcock's Psycho is famous for a multitude of reasons. First of all, this was far from one of the first horror movies ever produced, but for some reason, the fact that horror was being marketed to a wide audience scared the hell out of legislators. The movie made it through Hollywood's review board (barely), but some small towns boycotted showing the film in theaters because its imagery was "sadistic" and "degrading to the human race."