The Phantom Tollbooth, by Norman Juster

Join Milo on his adventure to find the fair princesses Rhyme and Reason. Meet new friends like the friendly watchdog Tock, or the grumbling Humbug. Bring the "Which" out of the dungeon, and bring Sound into the Valley of Sound. Swim back from conclusions and meet Dr. Discord and Dyne. Escape from the demons and bring the Math Magician and Azaz together again.

Norton Juster made a masterpiece out of The Phantom Tollbooth. I love the creative language. This book is good for ages eight and up.