I'm curious what you thought/think of Speaker for the Dead? To me, it's always been the odd-book-out, although I've only read about half of the series. It always struck me as the Empire Strikes Back to Ender's Game's Star Wars, in terms of being a very different style and content/setting/etc. Books like Xenocide and Ender's Shadow didn't surprise me as much stylistically.

Also, have you read any of Card's non-Ender books? I picked up Lost Boys years ago, it's very, very different from what I would expect from Card.