Some very obvious reference points in my case, but Hard to Be a God, Magnetic Rose (Memories), some of Bela Tarr's and Andrej Zulawski's work, and the strange post-apocalyptic films that came out of the former USSR have all had a profound impact on me. A lot of the soundscapes and textures I like to create I do with these works in mind. Weirdly enough, Martyrs belongs somewhere in there too..... kinda difficult to admit.
Beyond that, I have always gotten a very industrial, harsh noise vibe from Shozin Fukui's films (RIP). The Tetsuo series fits as well. I think part of it comes from the soundtracks and the schizophrenic, guerrilla-style filmmaking but it's hard to tell how much of that is actually in the films and how much is just association on my part since I first saw most of them around the same time I was getting into noise.