Before Captain Underpants Dav Pilkey was busy doing a lot of other great books. I love The Paperboy. It's simple and poetic and really gives you the feel for what it's like to be a paperboy. It was first published in 1996.
I love spreads like this:
It's hard to ride a bike
when you are loaded down with newspapers
But the paperboy has learned how to do this,
and he is good at it.
All the spreads are blue and black and dark green until the last few pages when the sun peeks up above the trees and colors a few lines of sky orange and yellow. Then the paperboy tiptoes back to bed...