Yaaaas, everything Dana said and definitely Tamora Pierce!

Well, anything by Robin McKinley except Deerskin, I think. That's still a bit too adult for me, although it does have wonderful dogs.

LeGuin's Annals of the Western Shore, which are YA and deal with power and oppression in interesting ways while still being (I think) interesting stories.

Rosemary Sutcliff novels -- they're set in Roman Britain, far enough away to be functionally fantasy. Similarly, and more modern: Gillian Bradshaw's historical novels, like Beacon of Alexandria and Dark North.

Michelle Cooper's Montmaray novels, which are sort of AU but mostly historical fiction. (But wonderful and everyone should read them.)

Guy Kay's Fionavar Tapestry (although it has a non-graphic rape scene). (I don't recommend most of his other novels for reasons too complicated to get into here.)

Has he read Garth Nix? The Sabriel books are good, and age-appropriate.

I read the Tearling novels this last year: they're probably too dark for him at this age, although they are technically YA.

John Marsden's Tomorrow When the War Began and its sequels, although I think it needs some examination for the racist implications of the premise and execution. It's still excellent adventure stories with serious investigation of war-related trauma.

Oh, oh! Kate Elliott's Court of Fives sequence, which can be described as American Ninja Warrior meets Little Women in a colonized East Africa. Also YA.

Oh, and of course! Megan Whalen Turner's The Thief and its sequels. Don't tell him ANYTHING. Just read them.

For graphic novels, I highly recommend Digger by Ursula Vernon. It's brilliant and everyone should read it.

Summer in Orcus by Vernon (under her T. Kingfisher pseud) is an excellent portal fantasy with a pre-teen heroine.

Hope that helps, and I should mark this because my nephew turns 10 soon and will want new reading material...

Skullduggery Pleasant series

Updraft

You all are the best. I knew I could count on you. Thank you!

Oh man. Reading The King Must Die and The Bull From The Sea gave me a bigger Greek mythology crush than the big yellow D'Aulaire book of stories did. Good times! Even if I was a bit young for all the sex scenes.

Clive Barker's Abarat is YA friendly and if you get the older editions the colorful art is amazing.

Is he too young for Dune?

Read on, young person!

John Bellairs' The Face in the Frost is a must-read.

C.S. Lewis' Narnia books might be a good choice if he doesn't regard them as kid stuff.

Charles De Lint's Moonheart isn't a classic, but might be worth a look.

Marion Zimmer Bradley's Lythande collection is pretty good, and though it deals with some adult themes regarding gender I don't think there's anything graphic.

Is Christopher Stasheff's work still in print? I remember The Warlock in Spite of Himself and The Warlock Unlocked, in particular, as great fun. I remember the first as a bit suggestive in a couple spots -- for example, a woman turns herself into a mouse and runs under a man's clothes. No details, though -- we're talking no more graphic than mildly PG-13, if that.

Question for the Literary Hivemind:

Do you recall a science fiction (or possibly fantasy) novel in which people lived their whole lives in tree because the ground was acidic and would dissolve them?

Thanks!

Kate, an oldie that I liked was Joy Chant's Red Moon, Black Mountain.

Oh, and of course! Megan Whalen Turner's The Thief and its sequels. Don't tell him ANYTHING. Just read them.

Co-signed. Like, a lot.

Mercedes Lackey? Valdemar series was my first thought.

sumi, have you tried the What's the Name of that Book? section on Goodreads?