Hash and wine. At least that was the opinion of somebody I knew, long ago, who went to see 2001 A Space Odyssey in the theaters numerous times, each occasion under the influence of various substances (acid, pot, mesc, various pills, speed, etc.).

Good luck in finding decent hash - I haven't seen any hash, good OR bad, in years. They had it in Amersterdam and Christiana (Denmark), but I didn't buy any. If I had (gotten some), I probably wouldn't have left, lol.