I really can't find my copy, but I suddenly got nostalgic and had to look for this book! This was my FAVORITE when I was a kid, and I have nothing except fond memories of Arthur and his experiences in this beautiful story. I recommend this book to any child who loves fantasy or just a really charming story. Out of all the books I've read (and there are a lot) in my life, this is the one I always come back to in my memory when someone asks me what my favorite book is.
Edit (2009): FOUND MY COPY! After buying a replacement, too! I'm rereading it as soon as possible. It's still my favorite story from when I was little. I remember finding it in a secondhand bookstore and falling in love with it. I even did several book reports on it and forced my English teachers to read it, too.
I don't agree with the critics' reviews. As an aspiring novelist, I see their points, but as a kid at heart, I see nothing wrong with the characterizations or setting. The story is written for children, and it is what it is, and fulfills what it sets out to do: it creates a wonderful story about dragons and humans in a quiet American setting, with some beautiful original mythology about the moon that has stuck with me over the years, and the characters (Mordechai!) are unforgettable.