I've got two little girls, so I'll pick up any books that features strong female characters with big dreams for the future.
"Grace for President" is one of those books. Grace is horrified when she learns there hasn't been any female presidents, so she runs for president of her class -- against a popular boy who wins the science fairs.
Not only is there a great message in the end, it explains the electoral collage -- which is a bonus for adult readers who find it confusing.
** This is the beginning of a new series of favorite picture books in the household. With a second-grader, she has to read 20 minutes a day. And picking among her favorite books helps. But, let's be frank, these are really my favorite books.