Leonardo the Terrible Monster by Mo Willems is another new favorite in our house.  I love the stye of this book.  One part of the story reminds me of Alexander and the Terrible, Horrible, No Good, Very Bad Day.  I really enjoy reading this to my 3 year old.  She likes it a lot as well.  It is a simple little story about Leonardo, a monster who can't scare anyone.  When he finally gets determined to scare the tuna salad out of someone, it doesn't go quite as he planned.  The book has a sweet ending and will now be included in my list of favorite children's stories.