Lumiere shorts (1895)
Birth of a Nation (Griffith, 1915)
The Cabinet of Dr Caligari (Wiene, 1920. Though in some ways it was also a dead end.)
Battleship Potemkin (Eisenstein, 1925)
Metropolis (Lang, 1927)
Un Chien Andalou (Bunuel, 1928)
Snow White and the Seven Dwarfs (Disney, 1937)
La Regle du Jeu (Renoir, 1939)
Citizen Kane (Welles, 1941)
Rome Open City (Rossellini, 1945)
Bicycle Thieves (De Sica, 1948)
Rashomon (Kurosawa, 1950)
The Seventh Seal (Bergman, 1956)
Vertigo (Hitchcock, 1958)
Breathless (Godard, 1959)
Psycho (Hitchcock, 1960)
8 1/2 (Fellini, 1963)
The Godfather (Coppola, 1972)
Taxi Driver (Scorsese, 1976)
Star Wars (Lucas, 1977)
The Terminator (Cameron, 1984)
Pulp Fiction (Tarantino, 1994) 

Sorry, a quickly drawn up 22 (was more, but i cut out some.) Some made immmediate impact, others grew over time. Heaven's Gate was inadvertently influential. Goodfellas, Close Up, Toy Story, Hiroshima mon Amour, L'Avventura, Tokyo Story, The Passion of Joan of Arc, Les 400 Coups, L'Atalante, Voyage to Italy also influential. Opinions of Cahiers du Cinema critics in the 50's.