OK, first the easy-to-watch blockbuster classics: everything made by George Lucas from 1970 to 1983, everything by Spielberg, Scorcese after 1980, Hitchcock, Mel Brooks until Spaceballs, every Monty Python film, some hong kong films by golden harvest, Exorcist, Alien, Bond flicks... you know, the good classic stuff...

Then moving to more complex stuff:

Pretty much everything made by Stanley Kubrick from "Paths of Glory" to "Eyes Wide Shut"
Orson Welles, specially Citizen Kane and Touch of Evil directors cut.
Kurosawa, specially 7 samurai, kagemusha (cant spell), ran, rapsody in august and yume.
Everything by Fellini, specially Fellini's Rome and Amarcord
Casablanca
Brazil: "O pagador de promessas", Central Station, City of God
M
Jerry Lewis's "Which Way to the Front"
Roberto Begnini's Life is Beautiful and Il Monstro
Terry Gilliam: Brazil, 12 Monkeys
Japanese art cinema, like Dolls and Taboo
Japanese anime films, like Grave of the Fireflies, Barefoot Gen, Wings of Haneimase (cant spell), Akira, Ghost in the Shell 1, End of Evangelion...
Harold LLoyd's Safety Last
Chaplin from the kid to great dictator
David Lynch, specially Eraserhead and Elephant Man
Anything written by Charlie Kaufman
Anything by Polansky
Waking Life
Kevin Smith's Clerks

I... suppose that's it.