Mo Willems has some incredibly popular books available - including the 'Pigeon' series. This books, however, will remain one of my all time favorite children's books. It's about Leonardo, who just can't scare anybody, and has to learn that there is something more important in life than being a scary monster.
Finally, for the night, an author I found just this month. Michal Hall makes shapes exciting. This book is about a square that thinks he's perfect until he gets torn up and realizes he can be so much more. I read this book five times today, and still not sick of it. Plus, it has great opportunity for quality art time with the kids.