Epic movies

What is the film equivalent of progressive rock? (Just as I write that, Pink Floyd's The Wall springs to mind). I'd like to see a movie that's like 10 hours long, a true epic. Not overly concerned with graphics or special effects or sexy actors (or actresses for that matter, or should i say act-people), like that useless, overrated piece of junk The Matrix, but with intellectual/artistic themes. The Odyssey would be a good place to start, I think.