In chronological order:
Gates of Heaven
The story of a man, a dream, and the pet cemetery he birthed.
No trailer I can find, but here's a great clip:
Definitely my favorite documentary, and maybe my favorite movie of all time. Sui generis, capturing the eccentricities of a small town in the days before the global network made everyone a potential filmmaker and/or potential star.
Again, no trailer- here's one of my favorite clips.
The Thin Blue Line
The film that invented the 'dramatic reenactment' and that should have won the Oscar.
Again, no trailer, just a mini-feature:
Vernon, Florida is my favorite Morris film but Mr. Death is his best, digging deep into a particularly vile, myopic strain of American conspiracy mongering & delivering as scathing a portrait of its protagonist as any you'll see committed to film. The evenhanded, nonjudgmental style of Morris' work magnifies the devastating impact of his films revelations, making it a rarity in his ouvre- a film I rarely re-watch.
That said, if I ruled over earth like Ming the Merciless (Max von Sydow edition), I'd make it required viewing for all adult citizens.
I note that the poster needed to make this comment:
Anyone posting anti-holocaust propaganda expectthat your replies will be deleted.