The Very Hungry Caterpillar by Eric Carle is one of our favorite books. We have the board book and love it!
This book is especially great right now because we are learning about caterpillars and what they eat with our own pet caterpillars. K loves finding leaves for the caterpillars, and honestly I think they are over-fed, but that doesn't deter K in the least.
The board book has different sized pages which make this book especially fun because it's different and easy for little hands to turn the page. The story is cute and entertaining for little ones, and it's a book I can stand reading over and over (and over).