Can I add Cryptonomicon by Neal Stephenson to the list? It's a very complex (and somewhat geeky) mutli-layered story covering technology, cryptography and the story of a family from WW2 to the current day. The only real problem with it is that Stephenson REALLY can't write an ending to his books! That aside if you like intelligent Sci-Fi and a bit of geekery then I can highly recommend some of his other works - snowcrash and diamond age