You should pick up a collection of Frog and Toad stories. I read them because I have little kids, but they are genuinely great little with stories. The stories are simple, but it is amazing how well developed the two characters are, and how they play off each other in different situations.

Arnold Lobel is also just very funny. Grasshopper on the Road made me laugh out loud the first time I read it my kids. The opening story about beetles that love morning ("The Club") feels so timely.