What is the best movie that you've randomly stumbled upon?

Once every two weeks or so, I like to watch a movie that I pick almost by random. I choose a genre I feel like exploring that evening, I exclude 1-2 "tags", and then look for a movie that gets my attention based on the title or something similarly minor. It's not about the ratings or notable actors, but just the concept.

That's how I stumbled upon The Endless(2017), which remains one of the most bizarre but also genuinely intriguing movies I've ever seen. I knew nothing about it prior to watching, read no reviews or opinions, and now I can totally recommend it to anyone interested.

And if you indeed are curious, it's a relatively slow and atmospheric horror that touches upon the topic of cults, the people involved in them, and those who manage to get out.

Anyway, what about you? What are some movies that you found by accident that turned out to be good/interesting/thought-provoking?