OK, don't hate me, this is JMHO
, but for the love of God please don't pick up the Wheel of Time. It's good, but about 4 books too long (so far, at this point there is no end in sight).
I agree with most of the other authors, I haven't read them all though. I just finished the first of the Harry Potter books, it is excellent writing. One author I can contribute is Terry Pratchett and his DiscWorld series. He's a brilliant satirical writer who writes stories that center around a fantasy word called, you guess it, Disc World. The first book in the series is called The Color of Magic. I know this isn't exactly what you are looking for, but his writing transcends genres.
As far as the particular type of book you're looking for, Dean Koontz is really good. As a matter of fact I have a tattoo of one of his book covers! (click on the book for a closeup of the pic)
Some of my favorites are Dragon Tears, Intensity, Ticktock, and Dark Rivers of the Heart. A lot of his novels are also on audio.