The Shining

This movie exists in a sort of unreality. Nothing quite feels right, characters occasionally do things that don't make sense, things happen with no explanation. And for a lot of movies that would be to their detriment. But here it just works so so so well. This whole movie is isolated from the real world, and Kubrick made sure that wasn't just a physical, but an emotional, a tonal construction. It's an otherworldly watch that demands you not be immersed in a world that feels like our own, but rather pulled kicking and screaming into a world that feels wrong, that is wrong. There are absolutely some flaws with The Shining, but no other movie, certainly no other horror movie, has felt quite like it.