There seem to be a lot of book threads lately (
1,
2,
3,
4,
5). Okay, maybe not
that many, but it seems like a large number over the weeks.
Having said that...
The Ender's series by Orson Scott Card ... a series I've enjoyed reading on varying levels. Just as a good read, for the views on humanity..
Earthfall series by Orson Scott Card (again) ... 5-6 books, enjoyed again on varying levels for how he works religion and faith into it as well as the human struggle.
Death Gate Cycle by Weiss and Hickman ... also wrote some Dragonlance novels, if I remember correctly. The first book starts off a bit slow, I think but is definately enjoyable towards the end.
New Jedi Order series, different authors ... Star Wars, 'nuf said.
Knight of the Word series by Terry Brooks ... (Running with the Demon, A Knight of the Word, Angel Fire East), good vs evil. Good fantasy, puts religion in a different light.
Dune by Frank Herbert ... duh.
LotR by Tolkien ... just getting into this one.
Y'know, I never realized how many of the series' I've read have something to do with religion. And I don't consider myself religious at all. Anyway...