I have to agree with conficted on the "Celestine Prophecy". I have the book at home but can't remember the author either. Although it is a fictional book, it did impact my view of spirituality. The whole idea of the book was that God is all around us, in nature, in our hearts. It mildly mock's organized religion.
Another was "Memoirs of a Geisha". Unfortunately, I can't remember the author of this one either, but it is an excellent story. Once I picked it up, I couldn't put it down.
Last but not least is "White Oleander" by Janet Fitch. Excellent plot. The main characted goes through the most horrible things possible and instead of feeling helpless, she finds strength within that she didn't know she had. She ultimately learns that happiness lies within yourself and comes out a winner in the end. I strongly recommend this book.
AMArie