Ebert's new Great Movie choice is ... Pink Floyd The Wall. He treats the film with diligence and respect, and I like his conclusions: it's not a fun movie, not uplifting, but exhilarating and daring and still very cutting-edge. I felt the same way, although I still think the movie has a misogynist streak that might not have been deliberate (and all the more distasteful for that reason).
Also striking is the movie/album's solipsism — not just in the sense that the Pink character is disconnected from his world, but there isn't even a single scene that involves him with another bandmember; the sum total of his experiences as a rock star involve sitting in a room being miserable. I wonder how much of that is a product of Roger Waters having been equally alienated from the other bandmembers (and vice versa) during the recording of it. Small wonder the band barely lasted one more studio album after that.