Heh, I think we are certainly in the minority. I thought the visuals were good, but not as amazing as I'd been led to expect, and the storyline was very bland to me, with characters I didn't particularly care about (with the exception of the one Sigourney played, but only because I am a Ripley fangirl
). I'd take an interesting storyline - not necessarily uberoriginal, but at least one that wasn't hackneyed and predictable - over fancy graphics any day. Saying that, I think the film worked at a 'myth' level - very archetypal characters, strong message of individual and social honour, a fairytale world, which might account for its appeal. I can certainly see why it is well liked.
The best sci-fi things I have seen are things that have convincing special effects but also have interesting and believable (in the context of the sci-fi world) plots - like
Firefly.