+1
The most disturbing movie, in my opinion, isn't held by a movie that is actually even moderately entertaining. I didn't find "The Girl Next Door" excruciatingly disturbing, but it surprised the holy-hell out of me when I watched it because I had a compilation of ... um .... discs that had ... the titles written in marker on blank discs, and I thought that it was the comedy about a guy with a porn-star neighbor. Clockwork Orange, Seven, American History X, Eden Lake, and numerous other considerable movies, I didn't find excruciatingly disturbing either. I am stalling, because I think the most disturbing movie is something like Human Centipede 2, for all of the wrong reasons. It was a horrible, horrible movie, that most accurately fists the bill as "Torture Porn", but that doesn't make it any less disturbing.