Ian Banks - The Wasp Factory
Terry Pratchett - Jingo
Michael Marshall Smith - Only Forward
Iain M. Banks - Use Of Weapons
Frank Herbert - Dune
William Golding - Lord of the FLies
Mark Twain - Tom Sawyer / Huck Finn
Eoin Colfer - Artemis Fowl
Louis De Bernieres - South American Trilogy
Good books though they are, I think you'll find both Sawyer & Huck were published somewhat earlier, 19th century in fact.
Id like to champion an unsung hero: The Dark Elf Trilogy by R A Salvatore.
Ok so it may not be structured to everybody's liking, but it gave us the greatest anti hero character of all time: Drizzt Do Urden.
This should have been made into a movie, instead of the movie about the hobbits walking for nine hours to a volcano:P.
Right.... now I really do enjoy fantasy books..., and I make a lot of allowances within the genre that I would never make for more general fiction. But, that can't cover up the fact that R.A. Salvatore is an
appallingly bad writer, I mean really, really bad. To be fair the original Dark Elf Trilogy are probably the best books he's ever written (have you read his Demon trilogy??? They're possibly the worst books I've ever read) but they're still nothing more than 1-dimensional pulp fantasy with goody-goody heroes, nasty evil baddies and some kick-ass fights.
Plus, in what way is Drizzt an anti-hero? An anti-hero is someone who is someone who acts contrary to the common concepts of heroism, someone you sympathise for or empathise with despite their flaws and vices.
Antiheroes are characters like Patrick Bateman in
American Psycho, like Alex in
Clockwork Orange, Jay Gatsby in
The Great Gatsby, Humbert Humbert in
Lolita, Hamlet, Raoul Duke in
Fear and Loathing... Drizzt is a traditional hero; strong sense of morality, stands up for the weak and abused, fights for what he believes in etc., it's one of Salvatore's flaws, that he is so incapable of imbuing his characters with depth or complexity.
If you want to nominate some really good fantasy novels I'd go for Tad Williams
Memory, Thorn & Sorrow trilogy... or his
Otherland series (though the latter is Sci-Fi not fantasy). Both are epic in scale, well written, and story wise are incredibly interwoven and intricate - within fully fleshed out realities, peopled by complex characters instead of the paper-thin walking cliches of Salvatore - (edit: Or almost any of Pratchett's Discworld novels)