The Wild Robot, #1 and #2 by Peter Brown
Harry Potter, books 1-3
Every Roald Dahl book
Holes by Louis Sachar
Sideways Stories from Wayside School by Louis Sachar
Every Kate DiCamillo book. The Miraculous Journey of Edward Tulane is a great place to start with her.
Bob by Wendy Mass & Rebecca Stead
Fablehaven by Brandon Mull
The Spiderwick Chronicles by Holly Black
The World According to Humphrey by Betty Birney
The Imaginary Veterinary series by Suzanne Selfors
Beverly Cleary is still great after all these years
Mrs. Piggle Wiggle still works too!
Percy Jackson and the Olympians by Rick Riordon
The Candy Shop War, #1 and #2 by Brandon Mull
The Box-Car Children by Gertrude Chandler Warner