A few additional recommendations
Like anyone asked, I know. 

  So I'm limiting these to those I haven't noticed anyone mentioning, or should be re-emphasized:
Garth Nix:  
Sabriel, Lirael, and 
Abhorsen (the latter just released).  Sort of YA but very interesting.
Philip Pullman:  
The Golden Compass (that's 
Northern Lights, I think, to the folks in the UK), 
The Subtle Knife, and 
The Amber Spyglass.  Again, some consider them YA, but they're very good.
Barry Hughart:  
Bridge of Birds, Eight Skilled Gentlemen, and 
The Story of the Stone.  Recently re-released in a handy omnibus edition.  Ancient Chinese-flavored fantasy.  Excellent.
Dianne Wynne Jones:  Just about anything, although she went through a rather "dark" phase that reflects a bit oddly in her work (examples of this would be 
Fire and Hemlock and 
Time of the Ghost).  Most recently I read 
Cart and Cwidder, which has about the best depiction of a family of D&D3e bards I could imagine. 

  As an added bonus, 
Howl's Moving Castle is being adapted into a movie by Hayao Miyazaki and Studio Ghibli!
I'll stop here for now.
-- Pazu