Or If Harry Potter is not in, Try...

Book Series:

The Crestomanci Novels and The Dalemark Quartet by Diana Wynne Jones
The Dark is Rising series by Susan Cooper
His Dark Materials series by Philip Pullman
The Redwall series by Brian Jacques
The Prydain series by Lloyd Alexander
The Chronicles of Narnia books by C.S. Lewis
The Time Trilogy by Madaleine L'Engle
The Wizardry series by Diane Duane
The Enchanted Forest Chronicles by Patricia C. Wrede

Individual titles:

The Hero and the Crown by Robin McKinley
Wizard's Hall by Jane Yolen
Ella Enchanted by Gail Carson Levine
The Secret of Platform 13 by Eva Ibbotson
Dominic by William Steig
The Perilous Gard by Elizabeth Marie Pope
The Hounds of Morrigan by Pat O'Shea
The Laundry News and Frindle by Andrew Clements

For Younger Readers:

Dragon Slayers Academy by K.H. McMullan
Time Warp Trio by Jon Scieszka