My favorite work of fiction would be a graphic novel series called "Blame!" Following that, huge fan of the original Ghost in the Shell animated motion picture, and the animated series "Stand Alone Complex". Reading the light novels for both of those cast them in an even more profound light. Everything by William Gibson, especially "All Tomorrow's Parties" and "Neuromancer". "Diamond Age" and "Snow Crash" by Neil Stephenson are great. The Foundation series by Issac Asimov is also really good. The Myst trilogy is also surprisingly good. R.A. Salvatore's Dark Elf trilogy of course, definitely a classic. I see the Annotated Chronicles of Dragonlance by Margret Weiss and Tracy Hickman has already been mentioned, fantastic series. I actually like Dragonlance better than any other D&D setting (except perhaps for Planescape). Also enjoyed reading the Sword of Truth series by Terry Goodkind, and the Wheel of Time series by Robert Jordan. Discworld by Terry Pratchett, and especially "The Color of Magic" were excellent. I Have No Mouth And I Must Scream by Harlan Ellison is also a must-read, legendary short story in my opinion. Everything having to do with the character Lestat from Anne Rice's vampire series, as well as The Claiming of Sleeping Beauty trilogy.
Man I have to cut it off here because I could spend hours doing this, going back and remembering all the awesome sci-fi/fantasy books I've read. I'll just say these are the first ones that come to my mind, that I remember the most.
