John Scalzi has one of those marvelous lists I can't resist. This one is a list of 9 Scifi Films You Should See That You (Probably) Haven't:
Flash Gordon: Space Soldiers
The Brother from Another Planet
Ghost in the Shell
The Iron Giant
I'm beside myself with o'er-weening pride that I have seen all 9.
The list at his site is annotated and each film has a link.