1. Mon Oncle
2. Play Time
3. Mr. Hulot's Holiday
4. Trafic
5. Jour de Fete
6. Parade

For me it's a tossup between Mon Oncle & Play Time. Mon Oncle wins by a hair because of its endearing story and the way we connect with the characters. Play Time wins on a technical & artistic level; it's visually freakin BRILLIANT, probably the most visually rich film I've ever seen (watched it 3x and keep seeing new things) but here he departed from the conventional storytelling and character development which we loved so much in Mon Oncle.

By the same reasoning, I docked Trafic a few slots. Once again it was visually amazing, the car crash scene was artistic genius, but here he veered even further away from conventional storytelling & characters, so it's much more challenging to watch. Might bump it higher if I watch it again.

All of them are fantastic. Honestly I enjoy them all pretty equally, but in very different ways. Also you can immediately see how Tati influenced later filmmakers. Terry Gilliam's Brazil is straight out of the Play Time universe with its lifeless greys and labyrinthine office settings. And Jerry Lewis's later films (Nutty Professor, Ladies Man, etc) seemed to imitate Tati's pacing & surreal style. I would even say the Zucker-Abrahams-Zucker films of the 80s (Airplane, Top Secret, Naked Gun) were directly inspired by Tati's visual absurdism as well as the concept of throwing lots of visual gags in the background which the audience may not catch on 1st watch. So glad I discovered this master of cinema.