Not SF, but watch "Ivan's Childhood", his first film. I saw it first on New Years Eve in Scotland. Me and my then wife went round to her friends house to pick her up for the usual celebrations. While the girls were getting made-up I started watching the film on the TV - I had never heard of it or Tarkovsky before, and I have no idea why it was on at New Year. They eventually came down and said "let's go" but I refused - "catch you later" - I just had to watch the film. Somewhat later friends mum came in and said "X why aren't you out with Y and Z" - I said "I HAVE to watch this". And I did, and then I went out and got pissed. It's a great film.