I know this is too obvious. I think that every book Sendak has made is an important contribution to children's literature. Let's not forget his magical collaberation with Carole King (thanks Bird) Really Rosie which I can sing by heart. Our favorite Sendaks are Where The Wild Things are, which Henry at age two was recorded reciting to Auntie Michaela. The Little Bear series and The Nutshell Kids series, a set of mini books (what is it with tiny books, I love'em) which grew out of the Really Rosie soundtrack, or vise versa.
I would love to elaborate but I am much to distracted with thoughts of voting tomorrow. With the hope of having a decent President. I am ready to get on my knees and pray. After praying, I will finally sew together those bibs and use my snap fastener for the first time.