Most uncomfortable movies to watch?

In regards to this, how does Nymphomaniac compare with something like In The Realm of the Senses? I still have't seen Nymphomaniac (it's hard to carve out THAT much time), but I am wondering whether it is worth moving up in my to-watch list.

Fantastic film. Solondz is maybe the best at making films about perverted suburbs?

Of the top of my head I would say Erasure Head and Blue Velvet, both by Lynch.

Slender Man (2018)

In the movie, the dumb friends search for one of their friends search history one of the friend uses Microsoft edge i never been shocked in my life after seeing that

Cannibal Holocaust

This also came up in the thread about oldest movie I've seen, but it's also the most uncomfortable movie I've ever seen, and that's Birth of a Nation, the silent 1915 epic, the biggest movie of its era and the one that explained how much the world needed the Ku Klux Klan. It's one of the first "big" movies, in the sense of a large cast, dolly shots, quick cuts, long movie, all of which revolutionized movies, but in the portrayal of just awful, cringe-worthy content. I've seen it in a festival since it has been kept as a monument to racism.