David Eddings: The Belgariad and the Mallorean
J.R.R. Tolkien: The Lord of the Rings (if you read any fantasy, this started it all)
Orson Scott Card: Ender's Game
W. Cleon Skousen: The Five Thousand Year Leap (U.S. Political theory, not fiction)
Anne McCaffrey: Dragonriders of Pern (any/all)
Isaac Asimov (short stories--novels are okay, but he's a short story writer: Nightfall, Bicentennial Man)
There are lots, lots more, but that's off the top of my head at work.