I have a 9 yo who loves to read and he suggested the following:

Orson Scott Card -- Ender's Game series
The Disappearing Spoon
1984 and Animal Farm
Farhenheit 451
Lord of the Rings
Sophie's World
Mysterious Benedict Society

I just finished the new Hillenbrand and I thought it was fabulous. Really gripping. It definitely has themes that are ugly (about a guy who was a POW in Japan), but I would let my 9 yo read it.

It's really fun to see other suggestions too.