5. Audition
Partly for the aformentioned foot-cutting scene but also the needles before that, however the main reason has to be for the thing in the bag, that was just messed up.
4. Inland Empire
This stands in for all Lynch's Films because they're all werid as fuck (except the straight story I guess) but Inl;and Empire is the weirdest. I don't think there is a rational explanation for the film, it's just disturbing.
3. Chinatown
This one isn't as weird or violent as the other films people have mentioned but I put it here because the overall morality of the story and it's ending especially is so unpleasent. The idea that the evil men not only go unpunished but are able to thrive is far removed from the traditional Hollywood ending, it's just such a bleak hopeless film.
2. Ichi the Killer
Another from Takashi Miike, this one is just two hours of violence, and weird violence at that. The torture scene alone puts it up there but the rest of the film is just disturbing as well. To give an example the titular Ichi spends most of the film crying but then cuts people apart spraying blood and body parts everywhere, and then he masturbates on them.
1. Natural Born Killers
Like Chinatown this is here because of it's dark, bleak tone. Unlike Chinatown Natural Born Killers also has vast ammounts of violence as well as torture, rape and abuse. There are no characters who aren't ammoral monstersor helpless victims. The constant shifts and sense of unreality help blunt the impact of all the unpleasentness but overall the sense of sickness bleeds through. If the film existed in a vacuum I probably wouldn't mention it here but what makes the film so disturbing in my mind is the fact that for all it's weirdness and its filters it manages to resemble the real world so strongly with the main characters being so similar with all the murder's and spree killers who've come before and since it was made, and also to the media's reaction to these people.