Alice in Wonderland pop-up book by Robert Sabuda. My best friend gave this to me for a birthday gift, and it's definitely one of the coolest things I own. The same artists has also done a Wizard of Oz Pop-up book.
Millie waits for the mail by Alexander Steffensmeier. Millie the cow loves to scare the mailman and chase him off the farm, until the mailman comes up with a plan that ends up pleasing everyone. Cute for preschool and up.