My list would be:

Jim Butcher

Michelle Sagara

Vicki Pettersson

Katie MacAlister(Vampire/romance)

P.C.Cast

Top Five Fantasy Authors (based on quality of work):

1. Tolkien.  Yes, he belongs on any top five fantasy list.  Most fantasy authors were influenced by him (and some flat-out copied the format in a truly terrible fashion).
2. Daniel Abraham.  His Long Price Quartet is great intellectual fantasy.  I like the world he created, and the books are intensely character driven.
3. C. S. Lewis. Narnia is truly a must-read.  I've still got the book collection from when I was younger, with the mildly psychedelic artwork.
4. Lawrence Watt-Evans.  He's more than just Ethshar.  I have most of his books, and still enjoy reading each one.
5. Neil Gaiman.  While I must confess to never having read more than two issues if The Sandman, I have loved the rest of his work since I first read Good Omens.  DW was even nice enough to locate Neverwhere on DVD. 8D
6. Robert E. Howard.  I've got to list him, even though he runs the list over.  Conan is the quintessential Sword-and-Sorcery fantasy work, and the basicness of the plot makes for great mind-candy.  Never met a wizard who couldn't be stopped in his tracks with quickly and accurately thrown rock (or head, or whatever else comes to hand).  Yes, the stories have racist and euro-centric themes, not often even thinly-veiled, but so did most fantasy from that era, it's a product of it's time.  I've actually collected as much Howard as I could, from Conan to Solomon Kane, to Dennis Dorgan.  Hint: it's all the same plot, different settings. ;)

A few others that I did not see listed that would be in my top 25 would be Kim Harrison,Kelley Armstrong, Libba Bray, Sara Douglass,
Melanie Rawn, Sharon Shinn, Raymond E. Feist

If I was forced to pick five I would have to go with Nix, Shinn, Butcher, Mccaffrey, Kay - but in ten minutes that list could change entirely

1. JRR Tolkien
2. Douglas Adams
3. David Eddings
4. Jacqueline Carey
5. Robin Hobb
 

Honorable Mention: Terry Goodkind, Robert Jordan, Garth Nix, Tamora Pierce (YA), Meredith Ann Pierce (YA)

1.Anne McCaffrey-The Queen of both SF and Fantasy!

2.Mercedes Lackey-What can I say? Fantastic!

3.David Eddings-He has the cool ability to make you laugh and cry in the same paragraph.

4.Kristian Britian- Her books are so good! Fully of detail and unexpected twists and turns.

5. Andre Norton- I don't like them all, but the ones I do are really, really good.

1. Clive Barker
2. Lois McMaster Bujold
3. Sharon Shinn
4. Mercedes Lackey
5. Tanya Huff

1. Tolkien (Lord of the Rings, classic)

2. C.S. Lewis

3. Tad Williams: his otherland series was just so brilliant and creative: it's both sci-fi and fantasy, but more fantasy really

4. Weis / Hickman: DeathGate and Dragonlance are both so original and creative

5. Terry Pratchett

1. David Eddings

2. J. R. R. Tolkien

3. L.E. Modesitt

4. Steven Erikson

5. Michelle West(Sagara)

Honorable mentions: Robert Jordan, George R. R. MArtin, Jennifer Roberson, Melanie Rawn, Mickey Zucker Reichert and ... So many more!!!

Well, my favorites change depending on what I'm in the mood to read, but at the moment I would say:

1. Robert Jordan (first fantasy I ever read, and will always be my favorite series)

2. Raymond Feist

3. Mercedes Lackey

4. Kate Elliott

5. Terry Goodkind

I'm surprised no one (at least I didin't see anyone) mentioned Marion Zimmer Bradley. Unless she is not technically considered fantasy?

I have to say that I think Robin McKinley (I LOVED Deerskin :: Robin McKinley) and Diana Wynne Jones are fantastic.

I usually consider Marion Zimmer Bradley science fiction, because I only know and love her Darkover novels, which despite the horses and swords are in fact science fiction. In fact, she is in my top five in the Science Fiction forum top five post. The Arthurian stuff would definitely be considered fantasy, it's just not my cup of tea.

So, my top five here are:

1. Jacqueline Carey - The first Kushiel trilogy (Kushiel's Dart, Kushiel's Chosen, and Kushiel's Avatar) were the first books to inspire me to declare a favorite (prior to that I insisted that I loved too many books to assign that designation to any) and were so incredibly fantastic that when I finished Avatar I immediately started reading them again. And despite that high standard, Carey has yet to write a book that I don't love.

2. Patricia McKillip - This is a provisionary rank, as McKillip is the only author on my top five whose entire back catalog I have not read. However, everything I have read has been exceptional, and Alphabet of Thorn, The Forgotten Beasts of Eld, and the two novels that make up Cygnet are so perfect that I really think she deserves this ranking.

3. Robin McKinley - She would have been higher, but the last two novels have not impressed me as much as everything else she has written. Still, Deerskin, Rose Daughter, Spindle's End, The Hero and the Crown, and Sunshine are incredible.

4. Lois McMaster Bujold - It shocks me that Bujold is so low on this list, considering she has to be the author I re-read most often. The only explanation I can give is that the three authors I placed above her write predominantly fantasy, while Bujold has written far more Vorkosigan novels than fantasy novels. However, that tally is shifting, and she may move up accordingly.

5. J.R.R. Tolkein - Of course Tolkein has to be on anyone's list. The only reason he is at 5 for me is that I'm still burned out on LotR from the hype surrounding the movies and haven't been able to bring myself to re-read them. Besides, he's only written four real novels, which is far less than anyone else on my list.

My honorable mentions: Elizabeth Bear, though she doesn't have much true fantasy; Orson Scott Card, Sean Stewart (a little-known Canadian author I recommend anyone pick up).

Also, I highly recommend Marion Zimmer Bradley, C.J. Cherryh, and Sherri S. Tepper, but don't consider them fantasy authors.

1.) Robin Hobb - Farseer Series was one of the most riveting tales I have ever read.

2.) David Gemmell - This man has constructed some of the most amazing heroes in Fantasy.

3.) George R. R. Martin - I've never seen so complicated of a plot come together so well.

4.) J. R. R. Tolkien - Only Fantasy books I have read multiple times.

5.) Jim Butcher - I have thoroughly enjoyed every book he has written.