I Am Going!. The humor is high quality as usual in this adventure, but what I noticed as my five year old was reading was everything that Mo Willems does with the font. I know it's kind of a literacy coach geekiness for me to talk about this, but the man is fontabulous (yes, that's a made up word and not even a good one like lebacle, but it's late on a school night.). You get all caps with a huge font with screaming endmarks to show Gerald's desperation, and later a very small font is used to show he has given up hope. Author's purpose abounds in this simple text.
With the expressive drawings, it would be interesting to tape over some of the thought bubbles and see if children could predict what was being said. It would also be interesting to ask children if they were more like Gerald or Piggie after reading one of their adventures.
I also noticed that my five year old smiles a lot when she reads a book by Mo Willems. Kindergarten teachers need to add him to their author study baskets immediately.