1960 also came to my mind before i saw your suggestion; i think Breathless (Godard) is given as that year too. Also, Cloud-Capped Star (Ghatak), and Mughal-e-Azam (Asif)- Indian classics; Black Sunday (Bava), Lola (Demy), Les Bonnes Femmes (Chabrol), Le Trou (Becker), Lady with a Little Dog (Heifits). Dates aren't always accurately given; i understand the imdb is more trustworthy than most, haven't checked these.

What about 1953: Tokyo Story, Ugetsu Monogatari, The Earrings of Madame de, The Wages of Fear, Voyage to Italy, and Monsieur Hulot's Holiday (this may be 1952).

1955: Pather Panchali, Ordet, Lola Montes, Diaboliques, Tales of the Taira Clan, Floating Clouds, Bob le Flambeur, Smiles of a Summer Night, Death of a Cyclist.

1966: Andrei Rublev, Persona, Balthazar, The Battle of Algiers, Closely Observed Trains, Two or Three Things i Know about Her, The Rise to Power of Louis xiv, Le Deuxieme Souffle, Diasies, Tokyo Drifter, Here is Your Life.

Of recent years, 2000 seems strong: Crouching Tiger Hidden Dragon, Amores Perros, In the Mood for Love, A One and a Two, Dancer in the Dark, Blackboards, The Circle, Solas, Show me Love, Code Unknown, Himalaya, Eureka, Werckmeister Harmonies... Time will tell.