I've been told that I have a simple sense of humor.
Sounds bad doesn't it?
But, simple is the reason I really like Mo Willems' Elephant & Piggie books.
These picture books have simple text and simple illustrations that let the characters personality and relationship tell the story. Not to mention they make me laugh out loud. The facial expressions alone are enough to induce a giggle. Try them out and see if they don't make you smile.
Check out his website: http://www.mowillems.com/