A chronically bored boy goes on a fantastical adventure in a land of words and numbers.
This 1961 children's novel makes a lot of "best of" lists of children's literature, so I decided to see what I'd been missing. It's a little odd, in that it's a fable about grammar, spelling, logic and math.
In some ways, it reminds me of "Alice's Adventures in Wonderland" by Lewis Carroll in that there's a lot for an adult reader to comprehend that may be lost on kids. (I'm thinking, for example, the caucus race in Alice, and the Which's tale of the banishment of Rhyme and Reason in Tollbooth). They're both the kind of books that gain new appreciations with rereading - especially if you've aged, learned, matured, or experienced more in the intervening time.
I listened to the first half of the book as an audiobook, then read the second half in paper. I enjoyed both forms, but you miss out on Jules Feiffer's renowned illustrations if you don't have the book. Of course, with the book you miss out on dramatic characterization (my audio version was with Norman Dietz, but there's also a version ready by David Hyde Pierce). Either way you win some and lose some.