The Chronicles of Prydain keep coming up as another classic series I should have read but never did. The first, The Book of Three, is very simplistic in plot and device. I don't know what kids expected in 1964, but I felt like for today's Harry Potter world kids can be trusted with quite a bit more depth.
Still, the story and characters were somehow endearing. I'm happy to recommend book one to my favorite 8-years-old-and-up readers.
On to book two!