Redwall was my favorite series growing up! My brother and I read them, staggered by a few years, and also watched the animated show together. I have read all but the last 1 or 2 books that were published, and now I'm probably going to have to reread the entire series.

I enjoyed The Castaways of the Flying Dutchman books, also by Brian Jacques. They have adventure, fantasy and riddles/mystery, similar to Redwall, but focused on humans instead of animals.