Eraserhead is pretty fucked up and disturbing.  Any David Lynch movie is, but Eraserhead fucked with my head the most.  Also Pink Flamingos is hilarious and way fucked up.  And The Last Temptation of Christ is pretty out there too, considering it not only creates an alternate ending for the Jesus story but Willem Dafoe plays Jesus.  Willem Dafoe as Jesus is both fucked up and disturbing.

any japanese horror movie

Suicide club, one missed call, uzumaki, Ichi the killer and about anything by Takashi Miike

I definitely have to be in a specific mood to watch Troma. They try to walk a really fine line between fuck it, lets just have fun and we’re too cool to try. Take that, THE MAN! but when they cross over that line, it’s really apparent. Tromeo And Juliet is a really good example of them just trying too hard to not try. Pisses me the fuck off every time I try to watch it. Don’t know if that clarifies but the point is I completely feel ya on the like and don’t like them thing lol. 

It seems like I’ve heard that they did a “normal” movie but I haven’t checked it out. 

wiked one said
The human cinaped….is fuking discusting…

There wasn’t anything that I thought was disgusting. Maybe the poop scene but that scene had to happen at some point right? I mean, everyone was thinking it even if they knew nothing about the movie coming into it. Tom Six kind of had to put it in and even then he didn’t linger on it. It was done as artistically as a scene like that could possibly be. He showed the scenario, explained how it affected the centipedes morale and moved on to the next scene. The people that say that about it, at least I’ve found, haven’t watched a lot of foreign or indy horror. Human Centipede was really uncomfortable. Like, I sincerely felt terrible at the end of that movie. That’s a feeling that most horror movies don’t do anymore because it usually fails. People always treat it like a dare, try to puff their chest out and say it wasn’t scary (wasn’t meant to be) or try to blame something else on them feeling the way they do after it’s over. Man, I’m sure a lot of people on this forum are way smarter than me and have watched more horror than me but for what it’s worth; I would say that Human Centipede is the best horror movie we’ve had since The Exorcist. There. I fuckin said it and I stand by it.

human centipede….  

Tusk, Perfume, and Antiviral are probably the most fucked up movies I can remember.