Woody Allen's Sleeper.
This has got to be in my Top Five Films.
If anyone has never seen it, get the video. I know it's a comedy, (it is very funny) but it uses all the Science fiction themes, cloning, cryogenic freezing, all powerful dictatorships, genetically engineered vegtables, robots, some useful household gadgets that aren't g-rated!
Even though it's from the '70's it hasn't dated. There are some really good scenes (too many to mention)- but the 200 year old VW Volkswagon that starts first time, giving him 20th Century photographs and asking him who the people were.