Sheila Ruth from Wands and Worlds, Charlotte Taylor from Charlotte's Library, and Tanita Davis from Finding Wonderland all attended the North American Discworld Convention earlier this month. The three of them served on a panel recommending YA fiction for fans of Discworld author Terry Pratchett. Sheila and Tanita both have posts on the event. Charlotte, who was the panel's moderator, has the list of books they recommended at her blog. A number of them are titles or authors I'm familiar with.
For instance, I haven't read The Book of Lost Things by John Connolly recommended by Tanita. But I have read another of his books, The Gates, an adult book with a child main character, definitely an option for YA readers.
I also haven't read the Diana Wynne Jones titles Tanita recommended. Faithful OC readers know I'm a big fan of her Chrestomanci books. They do have a Pratchett-like feeling--a developed world, some recurring characters, definite wit, and sophisticated writing.
Sheila recommends all the Bartimaeus books and both Lonely Werewolf Girl titles. I'm in total agreement.
One of Charlotte's suggestions is the Skulduggery Pleasant series. I happen to be reading the 5th book in the series now, having purchased 5 and 6 for my...yes, YA...niece's birthday. They just came my way a couple of weeks ago. Reading my niece's copy and knowing it's hers because of me makes me feel like one fine aunt.
Now that I think of it, I've given her a Bartimaeus book, too. And at least some of the Chrestomanci books. Oh, my gosh, I've given her at least one Tiffany Aching title! That's Discworld!
I am a stellar aunt.