10 speculative fiction books I consider among the best ever

This is from a challenge from Larry over at Of Blog of the Fallen:

What are 10 speculative fiction (the definition of which is left up to you, of course) would you say are among the best ever?

Here is my attempt in no particular order:

American Gods by Neil Gaiman

The Time Machine by H.G. Wells

Forever by Pete Hamill

Calculating God by Robert J. Sawyer

The Eyre Affair by Jasper Fforde

Fool on the Hill by Matt Ruff

Brave New World by Aldous Huxley

The Time Traveler's Wife by Audrey Niffenegger

Journey to the Center of the Earth by Jules Verne

Lost Horizon by James Hilton

Please note Larry said "among the best ever" in his challenge not "the best" as this is more of an off the cuff list than anything else and is by no means comprehensive. I also do not define favorite as "best." If I did this list would be very different and would include the likes of Christopher Moore, Tom Robbins, and Walter Moers. Also, it was tough for me to leave out The Shadow of the Wind, but there is very little that ends up being speculative in the work. For me to be among the best there are a few qualifiers:

a: A work I have or would re-read. b. A work which is incredibly inventive. c. A work that is superbly plotted. d. A work I would highly recommend to anyone. e. A work with believable characters. f. A work that has made me think.