I just watched The Florida Project, and his performance in that is so amazing. It's crazy how watchable he is as an actor. You're so immersed in his role and the world around him. Despite being such a well known actor, you completely accept that he's Bobby, manager of the Magic Kingdom.
There's also The Lighthouse, a movie that completely lives or dies by his performance, and he puts on a fantastic show. It's a very stage play performance, but it's so fun to watch. The curse in The Lighthouse alone is one of the greatest pieces of acting I've ever seen. Such a powerful scene.
I can't believe this man hasn't won an Oscar yet. He's a complete gift to the film industry.