Sight and Sound put out two excellent lists every ten years. 100 best films of all time as voted by filmmakers and another list voted on by published critics. I prefer the filmmaker list overall but it’s interesting to see how the darlings wax and wane over the years. Citizen Kane dominated for decades but now it’s Vertigo.
I first learned about it like twenty years ago. Some of them really need a second or third viewing to click.
When I was younger, it seemed obvious to me that Grand Illusion is the greatest Renoir film, easy. Rules of the Game was a head scratcher. I never understood why it was so highly regarded. It seemed more dated and slow. But now that I’m a little older I can see what’s great about it a little more clearly.
The list does seem a little too top heavy with B&W films from the 40s but most days I find myself agreeing with that era being best.
https://www2.bfi.org.uk/greatest-films-all-time