All of Tarkovsky, Egoyan, Bergman, Antonionni, Godard, Hartley, Teshigahara, Kronenberg, Kubrick...(that's off the top of my head).  There is no greatest film ever made because there are too many masterpieces that, by their nature, cannot be locked down to comparison, but if an unfriendly government locked me away in a cell for the rest of my life and told me I could have only one film to watch I would choose Atom Egoyan's Exotica.
Some personal favorites: Face of Another (Teshigahara), LaAventura (Antonionni), Nostalgia (Tarkovsky), Autumn Sonata (Bergman), Surviving Desire (Hartley), New Wave (Godard), Crash (Kronenberg), Eyes Wide Shut (Kubrick), The Tenant (Polanski), 1984 (Radford), Pi (Aronofsky), A Pure Formality (Tornatore)...these off the top of my head, and the  American films I mentioned are a few exam ples  of good filmmaking at home.
I have a 