Tarkovsky's Solaris and Stalker, they are slow moving in a typically Tarkovsky way, but mesmerising, particularly Solaris. Blade Runner has been mentioned, but deserves another mention. Throw in Escape from New York, The Thing, and Big Trouble in Little China (Not Sci-fi but it rounds out the Kurt Russell/John Carpenter trilogy off nicely) for a fun time after the intellectualism of the previous three and we are done.
