*sigh* The commentard that pointed out that SF geeks will read through 409 comments hit the nail on the head. That's an hour of my life I won't get back, but I was delighted to find a few surprises in the comments - movies I didn't know about that don't look like they are complete crap!
@spoonsinger: "No Millennium' love? (not the TV series but the weird airplane disaster investigation time travelley film with Kris Kristofferson)"
I loved it - a glorious mess. I'm just bitterly disappointed that it's the only John Varley ever to grace the silver screen, despite the fact that he was supposed to be off working for Hollywood instead of writing SF in the 80s+90s. His body of work deserves better cinematic treatment (and yes, I know there have been a few cheapo made-for-TV versions of short stories).
Millenium reminds me about "The Twonky" (1953).
It's a bit dated now, but - y'know - Henry Kuttner and CL Moore!
+1 for Flowers for Algernon - made me blub like a little gurlie too, just like Silent Running (damn you, Joan Baez for cheap heartstring tugging). Although I saw the 2000 version with Matthew Modine.
Haven't seen mentioned so far:
Paprika - quite "Lathe of Heaven" in concept, with some genuinely mind-expanding imagery. Not your average anime.
WALL-E - if we're having Silent Running, I'm having WALL-E. Ludicrous premise, profoundly moving execution and characterisation.
Simone AKA S1m0ne - quite topical this one, with Al Pacino's virtual movie star getting out of hand (shades of Idoru)
CJ7 - from the director of Kung Fu Hustle, small boy finds an interesting alien toy.
Mirrormask - Drifting into fantasy rather than SF, but I prefer to lump it with SF (Somehow it Fits) to avoid being tainted with elves, dwarves and sodding dragons.
And no true SF nerd gets by without some love for the trashier end of the spectrum:
Split Second (1992). Not Rutger Hauer's finest hour, but worth it for the scenery-chewing by both him and his nerdy sidekick (dude from Taggart)
"We need to get bigger guns. BIG FUCKING GUNS!"