Pulp Fiction
I don't care that it's been co-opted by the film bros, it's one of the best ever. An intensely movie-movie that has more on its mind than the vast majority of American movies ever do. It doesn't coast along on its now iconic imagery, shock value, or bizarre character details; it also interrogates so much about iconography, philosophy, and cinematic norms while still being very funny and not being annoyingly self-aware. It's a masterpiece and I love it.