/r/PrintSF provides a list of its top 10 favorite novels:

1. Frank Herbert Dune
2. Isaac Asimov Foundation
3. Dan Simmons Hyperion
4. Orson Scott Card Ender’s Game
5. William Gibson Neuromancer
6. Gene Wolfe The Book Of The New Sun
7. Neal Stephenson Snow Crash
8. Douglas Adams The Hitchhiker’s Guide To The Galaxy
9. Robert Heinlein The Moon Is A Harsh Mistress
10. Neal Stephenson Anathem

That’s a very credible list of heavy-hitting SF authors. Although one could argue for Count Zero in the place of Neuromancer and there are several Heinlein novels that many might wish to see in the place of The Moon is A Harsh Mistress. Interesting to see Anathem make it, although that could be more of a vote for the author of Cryptonomicon than for the book itself.