I totally forgot to list two of my absolute favorite picture books (for big kids. Some of my favorite picture books *are* for little kids). Me and My Cat?  is not very long, but its humor just won't be fully appreciated by little people.
I, Crocodile  I like, not only because of the dry humor, but because the illustrations are by one of my favorite artists--Fred Marcellino. One of the other books he did was Puss in Boots , which by the way, *I* think the Dreamworks people were trying to copy when they made Shrek 2.