Just been looking through my DVD collection. How do you think the following films would measure up against "Avatar"?:

The Battle Of Algiers (Pontecorvo, 1966)
Blade Runner - Directors' Cut (Scott, 1982)
Les Vacances de Monsieur Hulot (Tati, 1953)
The Day The Earth Stood Still (Wise, 1951)
Seven Samurai (Kurosawa, 1954)
Tom & Jerry: The Cat Concerto (Barbera, 1946)
A Matter Of Life And Death (Powell & Pressburger, 1946)

etc,. etc.

Just a tiny selection from my DVD collection - think about the wonderful films made through the years - and then think about "the greatest film"... All choice is personal, of course.