Life is Beautiful (Must see in Italian)
Airplane
The Jerk
Full Metal Jacket
Band of Brothers Series
The Longest Day
Saving Private Ryan
Pulp Fiction
The Wind that Shakes the Barley
Lord of the Rings Trilogy
Star Wars (All of them)
Howard the Duck
The Wizard
Battlefield: Earth
Lenard Pt: 6
Oh...wait...MUST see movies.
Lets toss out:
The Cook, the Thief, His Wife, Her Lover
American Beauty
Event Horizon
The Bourn series
Heavy Metal
...Did anyone mention Godfather?
And...perhaps, second most of the others.
John Ford's Cavalry Trilogy
The Searchers
His Gal Friday
McCabe and Mrs. Miller
Out of the Past
Cat People (the original)
Vertigo
The Wild Bunch
Get Carter (the Michael Caine original)
High and Low (Kurosawa)
The Taste of Green Tea (Ozu)
Army of Shadows (Melville)
Dead Man
Here's a great list by the film critic Jonathan Rosenbaum. It has the AFI top 100 list side-by-side with his own picks.
1- Wings of Desire (Wenders)
2- Sansho the Bailiff (Mizoguchi)
3- Exterminating Angel (Bunuel)
4- Aguirre, the Wrath of God (Herzog)
5- Mulholland Drive (Lynch)
I can't believe nobody has mentioned...
1. The Great OUtdoors (Big bear...big bear chase me!)
2. The Cowboys (John Wayne classic)
3. The African Queen (Bogie & Hepburn)
4. Bridge on the River Kwai
5. Any of the Eastwood "Man With No Name" movies
Amores Perros - Mexican Pulp Fiction (Warning: Graphic dog fights)
The Pulp Fiction comparison of the last two is kind of cheapening to them, but a good way to get the idea across. Many interrelated stories coming together as one.