2001 was okay... just not intensely good. Too overly-intellectual - I like my intelligent thought with a good side-order of action, otherwise it seems like it's taking itself too seriously. Probably because between my family and art school, I've spent way too much time watching people try to create elite-art just to be elite and not because of intrinsic merits.
Waterworld, I loved first because of the set design. It wasn't just a rehash of the usual fantasy/SF themes... it felt like a real world, a real place. Also I liked the survival atmosphere - a place where every little detail matters because humans are living so close to death. And the sequence where Imola (or whatever that little girl's name is) is mouthing off to the evil bad guy about how badass the hero is, while shots of the hero sliding down chains and generally kicking ass are cut into it, was just hilarious.