I love the Tiffany books! I think they're better than quite a few of the adult ones, and have as many observations on the world as the best of them. I also really liked The Amazing Maurice, which is a riff on the Pied Piper story: talking cats and rats (there's a cause, which probably explains Gaspode) who have as much character and eccentricity as any of the humans, Like the Tiffany books, it's a YA one, but just as good as most of the adult ones (and better than a few of them).