Bicycle Thief. This is really the most important film you'll ever see and it happens to be Italian
8 1/2 by Fellini. Just watch it. This film is almost a musical, certainly choreographed, even though because of the way Italian films were made, the dialog doesn't match the characters' lips. And yet characters dance perfectly to the classical selections. If that doesn't make sense, good. If you dig his style, go to I Remember or La Dolce Vita.
Salo or the 120 Days of Sodom (or if you're squeamish, Gospel According to Matthew which is much less gruesome) by Pasolini. Yeah yeah you can dismiss this as a "shock" film or whatever
L'avventura, L'eclisse, La Notte by Antonioni. Pick one, if you like it you will end up watching all three. Get ready for a film that tells a story purely with images and only sparse dialog.
Germany Year Zero or Rome, Open City by Roberto Rosselini
Really fun picks that are less "important":
The Conformist by Bernardo Bertolucci
Investigation of a Citizen Above Suspicion by Elio Petri
Congratulations you are officially Italian. Please grow rosemary, garlic, and pepperocini from the vines of your stone house your eight dads gave you
Too lazy to link all those guys, just search em
How it's so damn good. It's ruined the entire medium for me, I'm spoiled now. How many albums are better than this one? Maybe like 10? You got Spacemen 3 + orchestra + choir + recording in a damn cathedral. I get an hour of divine music and then I have to go back to cavemen banging rocks together. I can't overindulge, then I'd ruin the album forever. I can't listen to this thing every day. What else am I supposed to listen to?