Then there's the gods of evil. This is one of the best treatments of evil deities I've ever seen. Normally D&D/D20 writers are content with a standard 'evil gods of strife/killing/itchy feet/etc. These gods are downright creepy. From the disturbing opening fiction where a novice priestess of Chemosh, god of the undead, earns her position by cold blooded murder; to the insane worshippers of Morgion god of disease, these deities get down right nasty. It’s an insidiously realistic form of nasty too. These gods are far more interested in the corruption of mortal souls then in the usual run of 'villainy' we as gamers are supposed to take seriously.
The best part is, you really get a feel for why people would worship these deities. It’s always nice to read a god-write up and feel like you might actually venerate him or her, or at least see why another person would. And when it comes to evil; having to think 'that might be me' when looking at a dark god's followers makes the god in question that much more unpleasant.
In conclusion, I've never been that impressed with Dragonlance's take on 'religion'. Until now. The book is a bit high priced, and there are some typos, but its all well worth dealing with. Check this out if you play Dragonlance at all.
*SQUEE* They love me! They really love me! Those are my evil gods they are talking about. That's my fiction! I really liked writing up that fiction. It was creepy enough to creep me out.