I bought "Adele & Simon" by Barbara McClintock for my daughter as a Christmas present, after seeing a good review in the New York Times. Sometimes I do well with gift books, other times I fail miserably. This book was a big hit.
Adele & Simon is a charming picture book about a brother and sister in Paris. Adele picks up her little brother at school, and he has his hat, gloves, scarf, sweater, coat, knapsack, books, crayons, and a drawing of a cat. In each two-page spread that follows, Simon loses one of his belongings. Don't worry, there is a happy ending when everything shows up again.
The pictures are what really make this book wonderful, and worth reading over and over. You have to search each detailed page to find the missing item, and there are lots of other things to find. For example, when Simon loses his books in the park, there is a line of little schoolgirls with hats who look suspiciously like Madeline and her fellow students (and why not, they live in Paris too!). The illustrations have the old-fashioned look of Kate Greenaway, who I loved as a child.
After the story, McClintock gives a description of the Paris location of each illustration, complete with historical information. We haven't read that part yet -- maybe when my daughter is a bit older she'll be interested. What she does love is the book's endpapers, which are a map of Paris with each scene from the book marked so you can follow Adele and Simon's journey.
At our house, stories about older sisters and little brothers are generally a hit (hello, Max and Ruby!) but I think many children ages 4-9 would love this book as much as we do.