(1) Life of Pi by Yann Martell
I read this book last year and really enjoyed it, and I also think it lends itself well to discussion. It's not a religious book, but it does have a spiritual vibe to it.

(2) Angela's Ashes by Frank McCourt
I know I voted against this one before but I've heard so many good things about it that now I really want to read it.

(3) When I Lived in Modern Times by Linda Grant
The title caught my eye and it looks interesting, but I haven't heard anything else about it.

(4) Holy Fools by Joanne Harris