I mean I loved David Eddings, and I think hes a great young-teen or precocious child author, but his stories, aside from being well-told, lack any kind of depth or meaning to make them particularly valuable, aside from his often humourous description of group relationships. It was probably how he described everyone functioning in a group that gave me an unconscious understanding of how to do so effectively myself, especially when I was living in a group, so I think it is valuable in that regard. I guess it has it's other moments, but the other series tend to touch on bigger themes and handle them in a better way than Eddings' cookie cutter, black/white, 100% straightforward story.

That's why I generally prefer stuff like the Malazan Book of the Fallen, because it has touched on some bigger societal issues when the Author kicks in through one of his characters and waxes philosophical for a while. The execution isn't always what I prefer, but the guy makes a point without belabouring it or beating you over the head with it. And of course, massive epics just appeal to me deeply anyways.

While I'm at it, let's throw the Chronicles of Narnia on that list, because I read that a lot as a kid and I'm pretty sure I can still give you a detailed summary of every story off the top of my head.