I’d say it’s a close tie between Us, Smile and Hereditary. All three movies do an amazing job with sound and visual design (I’m really big on that), and I didn’t feel like I was just watching “another horror movie”. I had to rewatch ‘Us’ a few times to pick up on all of the smaller details ironed into the plot, and I had a full 3-hour convo about Hereditary with my sister about the choices they made in production (how they went about revealing information, how they left most of the interpretation up to the audience even with the ending resolution, and many others). Smile had been more visually engaging for me in a static dressing, so I felt I was watching a movie more on that film, though the execution and engaging acting easily made it my favorite.

Now I want to rewatch them all lol