I've been reading through http://www.tor.com/features/series/advanced-readings-in-dungeons--dragons lately and thinking about what has most influenced my own world building and design. Even better, let's make it a top ten...
Way back when I was in school there used to be a second hand book stall that I used to check out before hitting the classroom. It was here that I first picked up most of the Eternal Champion paperbacks. The crazy psychedelic covers! How could I not pick them up? Liked Elric but Hawkmoon and Von Bek really blew me away. Read everything I could get my hands on; Dancers at the End of Time (meh), The Cornelius Quartet (genius), Second Ether, the short story collections (Behold the Man and The Black Corridor are wonderful), New Worlds. Moorcock's writing just seemed to click with me. I never liked all that "Ye Merrie Olde London Town" stuff, these books were a lot more current. They didn't hark back to a mythical past or try to ape some ancient epic and the characters weren't just two dimensional archetypes. Still love 'em.
Back when I first started playing D&D there just wasn't that much fantasy stuff around. You had to seek it out, hunting through second-hand bookstores and reading every word in that month's White Dwarf and Imagine magazines to try and find stuff you liked. Conan bestrode the world like he owned it. The first and best film had just come out and the Sphere paperback series with the Frank Frazetta covers were a must have. What tales! Red Nails, Queen of the Black Coast, The Frost Giant's Daughter. This was a world made large, with characters to fit. Awesome.
What do you mean it's not fantasy? It's got sword fights, wizards and a beautiful princess! I went to the cinema to see this when I was seven years old and I adored it. I couldn't afford the toys so I made the spaceships out of lego and treasured the occasional copy of the comic that I could get hold of. Science fiction films at the time were all low budget dystopian visions so Star Wars was a breath of fresh air. And it looked great (still does). As mainstream as you could possibly get but still cool. Iconic.
The Princess Bride
The film? It's a classic and well loved for good reason but I'm talking about the book. What do you mean you've never read it? You've never heard of the ZOO OF DEATH! You don't know about the secret missing scene you have to write off for or the previous most beautiful women in the land? Or Inigo Montoya's years in the wilderness training to become the greatest swordsman in the world? Come on, it's been in print since 1973! What are you waiting for?
Titus Groan / Gormenghast
I love these books. Bookends of an epic tale of two men, one a scullery boy who rises above his station and one the heir to the halls of Gormenghast with shades of Saki and Charles Dickens, the grotesque and the comic. A totally unique atmosphere that is impossible to imitate and so there it stands, alone and insular, in it's own time and space. When I'm looking for a touch of the gothic this is what I reach for. Mervyn Peake could write like no-one else.
Folk tale, Arthurian legend and celtic myth all weave seamlessly in this trilogy by Jack Vance of Dying Earth and Vancian magic fame. It's a masterpiece of storytelling and I love to just pick it up and read random chunks of it. Strange, magical and with plenty of heart, it's a fairy tale for grown ups and a blueprint for how to make a vibrant, living fantasy.
Excaliber / The Once and Future King
Cue Carmina Burana! Excaliber overshadows all other filmed versions of Arthurian legend like a colossus. Nicol Williamson's Merlin is definitive and the mix of music and visuals is breathtaking. T.H. White's Once and Future King is utterly tragic as Arthur turns from the innocence and potential of youth into a troubled king whose lands turn to ruin and whose doom is unavoidable. A raging diatribe against war full of the beauty of the natural world.
The Water Margin
Monkey? No way, it's The Water Margin for me every time. Lin Chung leading the nine dozen from Mount Liang against the evil bureaucrats of the Song Dynasty. Martial arts adventure with great characters, stories and the odd bit of philosophy thrown in for good measure. It was also totally unlike anything else on British telly at the time.
Fantastic People / Encyclopedia of Things That Never Were
Two anthologies of fantasy art with accompanying text by Allan Scott and Micheal Scott Rohan for FP and Micheal Page and Robert Ingpen for the Encyclopedia. These books are a lot better than they really needed to be. The art is wonderful and the entries are full of great little details and quirks. I've spent many a happy afternoon browsing through these books letting the imagery tumble around in my head. Full of wit and invention and well worth seeking out.
City of Saints and Madmen
I'm a sucker for the weird stuff and this book has it in spades. It has more ideas than most authors have in their entire careers. The city of Ambergris is built over an underground settlement of mushroom people (myconids?), includes humanoid squid (mind flayers?) a dwarf and semi-intelligent aquatic life and is teeming with detail. The stories are really great, full of word play and stylistic tricks and but never to the detriment of the flow of the story.
Damn, I've missed out Harry Harryhausen, Terry Gilliam, Viriconium, Book of the New Sun, Thieves' World, 2000ad (ABC Warriors, Slaine, Nemesis the Warlock and Zenith), Brotherhood of the Wolf, Lankhmar, Alan Garner, E.R. Eddison, Edgar Rice Burroughs, George R.R. Martin, Neil Gaiman and Final Fantasy VII!