I don't know if OUATIH was his best film, but I'd say it was his most fun. It gets better with repeated viewings too--as a lot of the scenes where not a lot happens offer a lot that I missed the first time around, a lot of atmosphere to soak up, like when you see the character Sharon Tate (Margot Robbie) watching the actual Sharon Tate for an extended period--it shouldn't work, but it does.