The film that really struck me was Ridley Scott's Blade Runner. That was a film I watched many, many times and found endlessly fascinating in it's density. I think the density of that film is primarily visual density, atmospheric, sound density, moreso than narrative density.
I've been in rehabs with hardcore heroin addicts who say, 'I've kicked the heroin, but I can't let go of the tobacco. ' I haven't smoked a cigarette in a long time. I like being clean now.