I have the complete set of all 14 canonical Oz books, and the complete Chronicles of Narnia. I also have copies of Anne of Green Gables (which, like Narnia, I first read as an adult), From the Mixed Up Files of Mrs. Basil E. Frankweiler (my 5th grade teacher read it to the class), Call Me Bandicoot (serialized in Children's Digest, the year I was given a subscription), and Ghosts and More Ghosts (one of the short stories therein, "The Marvelous Stamps from El Dorado," appeared in one of my elementary school reading textbooks).
I need to re-read Mixed-Up Files. I read it in elementary school and loved it.