I have maybe read about half of the books Andre Norton wrote; as I said, she was a very prolific writer! I just wish there were more of her books available as eBooks - I certainly expected more to be in the public domain, but then she only died in 2005 and her estate wasn't settled until last year. Maybe more will find their way into the eBook world before too long.
Part of my liking of her books is nostalgia, I imagine - oh for my long lost youth when the worlds of scifi were new to me!
I also liked her portrayal of human/other animal relationships - who knew there were so many telepathic animals, including humans, in the universe!
Should anyone be interested, here is a site that's all about Andre Norton and her books:
http://www.andre-norton.org/
Holly