I couldn't get into the Xanth books but loved the spirituality involved in the Incarnations books and then followed those up by reading the Aprentice Adept series. I think I first heard of Piers Anthony from a friend who was very much into his Xanth series.
The series mentioned by 519helvis Incarnations of Immortality by Piers Anthony is one of the first sets of books that I read late in middle school and early high school as they were coming out.
