Originally Posted by Wayward Clam
ALL of the following authors are extremely prolific, so if you like one book by them, you can find a lot more that they have written... and with the exception of Roger Zelazny, they are all still writing as well...
Ender's Game - Orson Scott Card - a classic sci-fi, cult favourite of geeks and kids who were gifted and outcast in school. Lots of strategy and tactics.
A Night In The Lonesome October - Roger Zelazny - Sheer creativity - written from the point of view of Jack the Ripper's dog. All the politics of Zelazny, mixed with classic horror, and a little bit of mystery. VERY cleanly written, beautifully plotted and nicely wrapped up at the end.
The Chronicles Of Thomas Covenant The Unbeliever - Stephen R. Donaldson. Epic fantasy in six books. Depressing main character that some people may not like, but absolutely brilliantly designed fantasy world, and very entertaining storyline...
The Farseer: Assassin's Apprentice, Royal Assassin, and Assassin's Quest - Robin Hobb - Extremely good "character" fantasy, with a protagonist and other players you find yourself caring about. Holds your interest throughout, few or no boring spots. Politics and a little bit of magic.