err... lots?
I am pretty much a bookaholic, have been since I was about 9 years old and I am now 50. I was hooked by variations of the Arthurian Legends from early on, as well as the October 1966 issue of
National Geographic, with its wonderful article on the 900th anniversary of the Battle of Hastings.
As far as early fantasy writing straight-up, I'd have to point to Fritz Leiber's Fafhrd & the Grey Mouser stories, Ursula LeGuin's
Earthsea books, Moorcock's Elric stories (though these quickly faded into the background for me), literally hundreds of tales of King Arthur, and, of course, Tolkein's
The Hobbit,
The Lord of the Rings, and
The Silmarillion.
But in many ways, it is my combined interests in political and social history, folktales, comparative religion/mythology, anthropology, sociology, art history, medieval and renaissance literature, and all the rest in a vast melting pot that informs my approach to rpgs in general.
Specific books and authors? Well, you have a few names from my early interests now. I could add other specifics, but very,
VERY few of them are actually fantasy or science fiction authors. I actually don't enjoy most fantasy writers ... or any other specific category. To use the clean version of the old adage, "90% of everything is garbage".