following the great feedback from the best album thread (and i will listen to many of the albums referred to) a best film thread is reasonable.
if you define greatness by popularity or sales then gone with the wind, the godfather, scarface,shawshank,E.T etc
I am currently watching memento which I love as it makes you think (the film goes backwards) , pulp fiction, theres something about mary (i know slapstick comedy always gets slaughtered by critics), scarface (yeah, I know) , the usual suspects, chinatown (the ending a bit karaoke though) .
metropolis and king kong are obvious contenders for fans of older films.