It's hard to pick one. Dune, Robots of Dawn (or foundation), short stories by phillip K dick are really good to. At one point I would have said Stranger in a Strange land and I do think it's an excellent example I just don't particularly share many of Heinleins views. What do you guys think in general? I know im missing tons of classics and newer stuff but I'm curious what you guys think is a great read SF wise.