The Magic Treehouse series by Mary Pope Osborne
The Secrets of Droon series by Tony Abbott
The Flashback Four series by Dan Gutman
Imagination Station series by Marianne Hering
Ms. Frogbottom's Field Trip series by Nancy Krulik
Ranger in Time series by Kate Messner
Whatever After by Sarah Mlynowski
The Kingdom of Wrenly series by Jordan Quinn
A to Z Mysteries series by Rob Roy
Geronimo Stilton series by Geronimo Stilton
Thea Stilton series by Thea Stilton
Dinosaur Club series by Rex Stone
Dragon Masters series by Tracey West