If you’re in the market to buy your (grand)kids a book or two for Christmas, you might be interested in some of the suggestions offered in this Mortification of Spin podcast.
It should go without saying but I’ll say it anyway: The Chronicles of Narnia (C. S. Lewis) should be at the top of every list for young children. [If you have no intention to purchase any of these books or are otherwise indifferent to their availability in your home, please report yourself to DFACS now]
On the lighter end, I’ll go ahead and recommend The Wingfeather Saga (Andrew Peterson) although our family is still only in book 2. Not exactly on par with the Narnia books but an entertaining read with more action. Short chapters make the reading seem more manageable and the characters and creatures are unique (the Igiby kids, Fangs of Dang, cave blats, toothy cows, etc).
Feel free to make your own recommendations by responding to this post.