I like Passporter and Birnbaum's, but I've heard that Birnbaum's is a little biased because they're the "official" WDW planning guide. I'm easily amused, I like the pretty pictures. I like any book that tells me something I don't already know, which is hard to find.
I thought it was worth mentioning the one I dislike emensely...The Cheapskate's Guide to Walt Disney World. The whole tone of the book is really negative. I feel like highlighting everything negative in the book and mailing it back to them to show them how much their book ****s. Here's an example:
"Main Street Cinema Once upon a time, they used to show old-time Mickey Mouse cartoons here. In fact, they paid homage to the Mouse who started the Kingdom by continuously showing his first cartoon feature, Steamboat Willie. But, alas, showing cartoons for free doesn't do much for the Disney bottom-line, so they have turned this theater into a store, where you can pick up stuffed animals and other cha-cha from the latest Disney video releases. If you've read this far, you shouldn't be surprised by this turn of events."
If you hate Disney, don't write a book about them. Oh, but wait...that wouldn't do much for the Lewis-Lacey bottom-line, would it?