Orson Scott Card's Ender series. But OSC has emphatically said it'll never happen, it seems he's biased against anime. :-(
Bit of a tangent, but what western books *have made* great (or not so great) anime? In trying to introduce my sister to anime, I tried to have her watch Dear Daddy Long-Legs, which is based on one of her favorite books. I thought they did a fairly OK job adapting it, but my sister couldn't get over the main character appearing to be significantly younger than in the book, and didn't like it at all.
I've downloaded, but haven't gotten around to watching, The Diary of Anne Frank. Anyone know if they did a good job?