Another vote for Watchmen!
More SF books I've really liked:
**broken link removed**
Anything by
Robert J. Sawyer--I've loved everything of his that I've read, and I think I've read most of it.
I have also really enjoyed what I've read from
Fred Hoyle, but at the moment the only titles I can remember are Element 79 and The Black Cloud.
I tend toward harder SF but I also really enjoyed Dan Simmons'
Hyperion Cantos.
I am ashamed as an SF fan to say that I still haven't read the Dune books.
Torben