Probably a typical list with a few more obscure entries. In alphabetical order

Baker, Scott - Esp. "Drink Fire from the Flames" (1986) and "Firedance" (1987). These two books are set at the start of the bronze age in Mesopotamia, when the king was a God and every trade guild (the potters, smiths, weavers etc) had their own special magic. One is left with the impression that even if the magic didn't really work, that this is the way the Mesopotamians might have viewed their place in the world. "Dhampire"(1982) is one of the best vampire books I have ever read.

Cooper, Susan. Her "Dark is Rising" series (1965-1977) is a great work for adolescents. Set in rural modern day Great Britain, it details the intiation of adolescent Will Stanton into an order of immortal magicians that has been fighting a battle against the forces of darkness for thousands of years.

Hobb, Robin (aka Megan Lindholm) This year I read eight of her 500+ page books in a week and half. I guess that means I like her stuff. Traditional Tolkienesque fantasy setting done as good as anyone is doing it right now. Engaging plots, a fine eye for details, very likeable, well-developed characters, and some wonderful human insights.

Lee, Tanith. I think she has published way about 50 or so books and way too many of them are good for me to list them. Originally she wrote a lot of Sword and Sorcery material, but her more recent stuff has been set in an alternate later day Renaissance Europe. Her characters have a decadent, gothy feel to them, and her prose can be very beautiful to read when she is at her best. If you want to see what one very productive writer's version of the creative process looks like go to Tanith Lee Manuscript. And the secretaries complain about MY handwriting. (Well actually it is about as bad as this. But NOT worse!)

Lewis, C.S. "The Chronicles of Narnia" (1950-1956). Brillant classic with a very Christian theme. Recent collections of this series put "The Magician's Nephew" as the first book. I think it belongs where Lewis put it, second from the last.

Pullman, Philip. The "His Dark Materials" series (1995, 1997, 1999) is nominally a children's series, and won the Newberry Award for best children's fiction. It is much more mature in tone than a lot of other supposedly adult fiction. I wonder if many parents know that the book with medal on the front of it in the children's section espouses atheism and takes quite open pot shots at the Catholic church.

Stewart, Sean To the extent that there is a cutting edge to fantasy writing, IMHO Sean Stewart is at its forefront. Most of his plots take place in Modern day North America or in the near future, but involve magical and not scientific elements. I suppose Tim Powers and Neil Gaiman are doing a similar sort of fiction, but I think Stewart does it best. Personal favorites are Nightwatch (1997) and Mockingbird (1998).

Tolkien - no first name necessary. no explanation necessary.

Zelazny, Roger - Could be placed in either the SF or fantasy category but most of his SF has read more like fantasy anyway. Zelazny specialized in giving ancient mythologies a modern twist.