Eraserhead (mostly because you'll have no fucking clue what's going on and so can inherently pull some sort of great philosophical BS out of it).
Wings of Desire (nature of Angels, immortality, etc etc)
The Man from Earth (the whole thing is just one big philosophy discussion, but I found it very, very interesting)
Wings of Desire (nature of Angels, immortality, etc etc)
The Man from Earth (the whole thing is just one big philosophy discussion, but I found it very, very interesting)