Pajiba has a list of the ten most confusing movies of all time. ‘Confusing’ is a bit of a pejorative term, though. For some of these, I’d prefer just complicated. The issue is whether the complexity yields returns upon further viewings (Primer and symbol for Pi) or whether it’s just so much jumble covering nothing very much (I’m looking at you, David Lynch entries). It’s been a while since I saw Videodrome, but I don’t remember that being especially confusing. Haven’t seen Synechdoche, New York yet.
Not on the list: Time Crimes — complicated but worth unraveling.