Dd12 is supposed to be reading a "challenging" book each quarter for her 8th grade lit class. They are having individual literary discussions with the teacher about the books they read and doing other activities surrounding these books. Each child has a different book, so s/he can read something totally different from the other students.
Last quarter dd read Lord of the Flies, which she didn't love but didn't totally hate. In general, I'd say that she likes futuristic novels, horror, and some realistic fiction when there is personal conflict with which she can somewhat relate. She used to like SciFi, but not so much anymore. I can't say that she's loved most of the classics she's read.
Some of the possibilities she's come up with for this quarter include Edgar Allen Poe's Fall of the House of Usher (which is most probably too short), The Jungle by Upton Sinclair, or The Bell Jar by Sylvia Plath. She's leaning toward The Bell Jar.
Does anyone know if there is anything in there that is grossly inappropriate for a 12 y/o? I must admit that she'd read things recently, like The Lovely Bones, that I'd probably rather she'd not and I'm getting to the point of doing less reading censoring. She's also read stuff like The Art of Racing in the Rain that she loved and that wasn't at all questionable, but those types of books probably won't constitute "challenging."
Given that she has been able to read pretty much anything up through college text books since she was about 8, I think that the only way to get to challenging is to go with older books that are written in less modern language, books that have been translated from another language, or books with themes that she might not immediately understand even if she can easily read the book itself. Unfortunately, a lot of books that fall into that category don't really interest her.