Here’s my recommendations. Even though I shouldn’t have to say this, please bear in mind that this is all my opinion. In no particular order:
Robert Jordan: I was a huge, huge fan until about book 6, in which not a damn thing was resolved or moved forward. I am now convinced that Jordan is a money-grubbing hack padding his series out to make maximum cash. Pity.
Terry Goodkind: Utter, shameless drivel.
David Eddings: Light reading, but The Belgariad was loads of fun – I’ve read it front to back several times. His other series aren’t much worth reading.
Ursula LeGuin: Possibly the greatest living SF writer. Her original Earthsea trilogy is splendid, though I’ve not read book 4.
Glen Cook: I don’t find the Black Company stuff to be as compelling as some do, partly because I find the alliterative names irksome and distracting. But they’re certainly gritty, and there are some fine ideas in there.
Katherine Kurtz: The first two Deryni trilogies were very good, though subsequent ones have been a touch overwritten. Still enjoyable and reccommended, but take note: there are a lot of unhappy endings in this series, where Bad Stuff happens to likeable characters.
Poul Anderson: I love his SF work. His King of Ys series is very ambitious, and richly written. I found it tough going.
Robert E. Howard: The original Conan stories (not the pastiches by other authors) are some of my favorites. There’s a reason why Conan has become such an icon.
Jack Vance: One of the finest prose stylists in the field. The Dying Earth and Lyonesse series are where to start, but his SF is pulpy-good too.
Gene Wolfe: I have the whole Book of the New Sun, but lost interest after the first book. I’ll try again some day.
Roger Zelazny: The first five Amber books should be required reading. I also enjoyed Changeling. His best work, though, is Lord of Light, one of the greatest SF novels ever written and every bit the equal of Dune. An amazing, amazing book.
L. E. Modesitt, Jr.: The only thing I’ve read was The Magic of Recluse which I though was quite fresh and enjoyable.
Stephen Donaldson: His stuff is dreadfully overwritten, but I’ve yet to pick up anything of his that I’ve been able to put down. It’s a car wreck I can’t tear my eyes away from.
Jennifer Roberson: Her Cheysuli books were well-written and reasonably fresh.
Joel Rosenberg: I’ve met him. He’s a cretin. My view of his work must sadly be colored by this knowledge.
Michael Moorcock: The Elric stuff is central to the modern genre and should be read by anyone with a serious interest. I like much of his stuff (the Elric, Corum, Hawkmoon, Von Bek and Eternal Champion sequences,) while other stuff (the Cornelius Chronicles) leaves me cold. I am also a fan of his work with Blue Oyster Cult and Hawkwind.
Mercedes Lackey: Generally considered a hack. I have no opinion, since I’ve not read any of her stuff.
Marion Zimmer Bradley: I think The Mists of Avalon is a great book. Her later fantasies are hard to stomach.
Katherine Kerr: I liked the first four-book Deverry sequence very much. I am waiting for the third series to all be out in paperback before reading any further. For those who don’t know, she’s a gamer – she used to write articles for Dragon, back in the Day.
Terry Pratchett: A genius. I loathe humorous fantasy and SF. His stuff is the exception.
George R. R. Martin: The first two books in his series are terrific. However, the thing was originally supposed to be a trilogy. Then it was supposed to be 4 books, then 5. Now it’s six books, with a 2-3 year delay between volumes. And King_Stannis says it may be seven. I hereby throw up my hands and refuse to read further until the entire series it out. I really, really hope that this series doesn’t become another Jordanesque fiasco.
Fritz Leiber: Not a big fan. I find much of his SF work terribly dated and I think his fantasy tries way to hard to be witty and clever, and usually doesn’t succeed.
Piers Anthony: SF/Fantasy’s most gifted hack. He is a writer with immense talent, but he chooses to squander it writing an endless, fetid stream of Xanth novels and other tripe.
Ray Feist: I liked Magician, and the wrap-up of the original Riftwar series was decent, but his later books have left me dead cold. I drifted off in the middle of the Serpentwar, having lost all interest. His Empire trilogy with Janny Wurtz is quite good.
Dennis L. McKiernan: There’s a reason why his Iron Tower trilogy is a near-clone of LotR – he wanted to write sequels to that series, but the Tolkien folks (understandably) said no. So he wrote an equivalent series, and then wwrote his sequels to that. If you can get through the Iron Tower, these later books aren’t so bad. Light reading.
Steven Brust: The early Jhereg stuff was very enjoyable. The last few have been much less so. But his non-Jhereg stuff is worth looking into. To Reign in Hell is particularly noteworthy.
Terry Brooks: A more important author than some would like to credit. Wholly without talent, orignality or writing skill – I was writing better stuff in my 10th-grade Creative Writing class.
Weis & Hickman: I’ve met Margaret Weis – a very nice lady – so it pains me to say that these books are a joke. Only in the field of game fiction can they be considered anything more than the lowest form of crap.
R. A. Salvatore: Maybe the best writer to come out of “gaming fiction.” By any other standard, a mediocre writer. Usually readable, at least.
Tad Williams: Good, though Memory, Sorrow and Thorn was probably 500 pages longer than it needed to be. A worthwhile read.
I’ve left off some old influences like Eddison, Dunsany, Peake and Cabell. Tolerance to these varies considerably. I thought Eddison was turgid, but I like what Dunsany I’ve read. Someday I will try to tackle Peake again.