What is the weirdest movie you've ever watched?

I don't know if it's the weirdest I have ever seen, but Repo Man (1984) is pretty weird.

Brazil

Salo.

Full Metal Yakuza.

Fantastic Planet

Rubber

I love how OP says weird and everyone jumps to disturbing. Bastard Out of Carolina. I win the latter. Weird? That's quite hard to say and depends on what you consider normal. How about a movie where people sit around and talk for an hour and a half, with one trying to convince the rest he's 16,000 years old? The Man From Earth. Good movie, too. Not disturbing at all. But weird. Or how about a Spanish language movie about time travel that actually works out damn near perfectly? Timecrimes. Might be less weird if you speak Spanish (traditional, not Mexican dialect—the movie was made in Spain). Also a good movie (it has English subtitles). Or do you want a weird movie that disturbs you a little? What about a movie about three weird late-teens who wreak havoc and get in all kinds of trouble? The Doom Generation. NSFW definitely. The three latter movies are on Netflix. The first is NSFL and probably not available on any streaming service (maybe the edited version Lifetime plays every now and then).

Old Boy is pretty strange.

Definitely Antichrist

The Green Elephant.

Chillerama!

Naked Lunch

Green Elephant

The Mask