All this talk of YA has generated an SF Signal Mind Meld collection of author recommendations.
MIND MELD: Young Adult SF/F Books That Adults Will Like, TooIt'll take you a good while to read through the replies here. Let alone how long it'll take you to look up the books at the library or on Amazon. And then you can get to reading! At least I've read a couple of them already.
It's interesting to see which ones got mentioned several times.