Ahh, yes, definitely Inkheart, etc. -- although I have only read the first one, and got sidetracked on other things before getting to the rest.
Do they read Where the Red Fern Grows at your school? When I was in school, it was a 4th grade tradition, and in my kids' school it's a 5th grade tradition. It's very sad at the end, though -- our 5th grade teacher has to bring someone else in to read the last bit because it makes him cry too much.
There are other old standbys -- Island of the Blue Dolphins, the Black Stallion books, etc.
