Rilla of Ingleside by L.M. Montgomery - I discovered this one when I got the box set of Anne books when I was 11 or 12. I was highly dubious about this one before I started it because who was this Rilla person anyway? I ended up loving it. There's not many books that show what life was like on the home front during World War 1 through the eyes of a teenage girl and none with such a realistic feel. This is my favorite Anne book to reread as an adult as well though I have been known to ugly cry through quite a bit of it.
The Westing Game by Ellen Raskin - This complicated and fun mystery has a little something for everyone. Besides the mystery there's all kinds of interesting characters and it a book that's easy to become involved in.
Summer of the Woods by Stephen K. Smith - This is for the younger set - think 2nd to 4th grade - but I think they'd really enjoy it. There is a bit of history involved but it's mostly about a group of kids solving problems and having adventures.
Little House in the Big Woods by Laura Ingalls Wilder - I remember being fascinated with Laura's life in this book. It's so foreign from everything I know that I couldn't help but be captivated.
The Secret Garden by Frances Hodgens Burnett - The secret garden, the rambling empty house, making new friends and creating a world where you fit in. What's not to love for a young (or adult) reader?
Chitty Chitty Bang Bang by Ian Fleming - This is just a straight up adventure story with gangsters and a flying car.
The Lion, the Witch and the Wardrobe by C.S. Lewis - While I didn't love all of this series as a child I adored this book and think it's probably the most child friendly.
Ophelia and the Marvelous Boy by Karen Fowler - There's a rambling museum which the children have complete access too, a mysterious boy who is hiding from danger, and a very very evil woman hiding behind a beautiful mask. It's a modern day fairy tale with an almost Gothic feel.
What children's books captured your imagination as a young reader? What books would you want your children to read?