The Hobbit & The Lord of the Rings,Another Fine Myth, various other "myth" books, Catch-22 ,Brave New World, Fahrenheit 451, Gulliver's Travels, A half dozen westerns by Louis L'Amore (I was on a western kick when in Jr high), Moby Dick, The Scarlet Letter, Huck Finn/Tom Sawyer/etc, The Art of War, Don Quixote,A half dozen R.A. Salvatore books, Into the Wild, Walden, etc, etc.
Way too many to list really. I tend to enjoy non-fantasy moreso than scifi or fantasy books, and particularly I like the classics. I think working in a library through high school instilled that into me.
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".
My first book was Treasure Island by Robert Louis Stevenson, I'm unsure what age I was, my memory is fuzzy.
Emm thinking back on it I would always have a book to hand (at the moment I'm reading a Collection of Conan stories I got for Christmas and Anne Rice's Queen of the Damned). As to listing what I have read it would be a interesting but not very successful feat.
I've been meaning to start reading some classic's, as in stuff from 18th-19th century, Dickens and the like.
I like modern fantasy, but prefer scifi (I am an electronic engineer by trade) and I will read anything if I run out of stuff; like an Agatha Christie novel last year - she's a really interesting writer.
It would be interesting to know how many books I have read, easily around 300, but maybe more? That averages around 10 books per year, so that would be conservative I'd guess, although I do prefer meatier books (just finished Duma Key by Stephan King; a nice meaty book).
The Hobbit & The Lord of the Rings by J.R.R. Tolkien
The Belgariad and the Mallorean by David Eddings
Foucault's Pendulum (Umberto Eco)
A TON of Edgar Allen Poe stuff
The Harry Potter series
The BFG (Big Friendly Giant), The Twits, The Witches by Roald Dahl
The Lion, the Witch, and the Wardrobe
The Golden Compass series
The Bartimaus Trilogy
A bunch of stuff by Neil Gaiman (books, not comics/graphic novels)
Angela Carters short stories (The Bloody Chamber)
China Mieville's Perdido Street Station
Scar Night (Alan Campbell)
The Anubis Gates (Tim Powers)
Song of Kali (Dan Simmons)
The book of Jhereg (Steven Brust)
Excellent, excellent book. Not an easy read though.
I've read a lot of non-fantasy and scifi, but as far as these genres are concerned:
When I was younger:
Moorcock's Elric and Corum series'
Leiber's Fafhrd and Grey Mouser series
Tolkein's Hobbit and LotR
Asimov's Foundation series
C.S. Lewis' Chronicles of Narnia
CS Friedman's Coldfire trilogy
Various Gaiman books (not graphic novels)
GRR Martin's Song of Ice and fire series
John C. Wright's Orphan's of Chaos (starting on this one now)
China Mieville's New Crobuzon books.
Lots of others, I just can't remember them all. I am sure I am leaving out some good ones too.