My favorite picture book growing up was The Very Hungry Caterpillar by Eric Carle. As a child, I had a paperback copy and it was well loved. I just adored the short pages with the little holes bitten through each page, and as the caterpillar ate more, the quantity of food increased and more holes in the pages were made. By the time he got to the big green leaf, he felt so much better...and so did I! I just couldn't get enough of that book! Now I own a hard back and it gets well used too!
As an adult, one of my favorite picture books to read at story time is Duck on a Bike by David Shannon. I love how duck goes around to each animal on the farm and asks them if they want to ride a bike. All the animals think he's foolish and such a show-off. Its not until all the animals realize they can ride bikes too. The art work in this animal fantasy makes the barn yard menagerie so realistic.
Another favorite I have as an adult is Children Make Terrible Pets by Peter Brown. This is another book I love reading out loud to preschoolers. I just LOVE how reality is turned around by an animal wanting a child as a pet. And how the mama bear tells her bear child that they want a pet, they must take care of it all the time. A hard lesson is learned, but its just so humorous!