John Q. Mayhem said:
Khador, the Protectorate of Menoth, Ios, and the Lord of Blades' country in the Mournland spring to mind. Granted, three of 'em are from IK, but still...this is a pretty sweeping statement.
IK is the winner for me, by the by. 371 pages of fluff...I really do think the IKWG is the first fluff-only D20 book.
I agree to a point, and I realize the statement is pretty broad. While Khador, the Protectorate of Menoth, and Ios could be made into bad guys or have evil means to an end, they are not by definition evil. Khador is imperialistic and expansionist, but not evil. The PoM are a bunch of religious zealots with extreme methodology, but not necessarily evil. And the elves of Ios are xenophobic and will kill intruders, but again, not evil. I'm not as familiar with Eberron, because it never leapt out and grabbed me, but IME most evil countries/organizations in Wizards/TSR products were VERY one-dimensional.
What I meant by a deep, compelling evil society is one that actually makes sense given the social/political/religious values of the area and people. While Khador, PoM and Ios could be portrayed as evil, they are not by definition. Canceri in Arcanis is, by definition, evil. It is a theocracy ruled by priests of a triumverate of gods, most of whose worshippers are evil. (In Arcanis, any god can have clerics of any alignment, so its not as easy to say all clerics of Sarish are evil- but most are). They have an iron grip on law, religion, and trade, but oddly enough the people in Canceri don't live in abject terror of their rulers. In fact, while they might grumble occasionally about taxes or brutal efficiency of the government, most of the citizens are fairly happy with their government, which they see as the last "enlightened" country in the world where the worship of their gods is not prohibited. The theocracy champions their faith, protects them from their enemies (the Coryani Empire and Milander), and the people of Canceri have been persecuted for their beliefs and genuinely socially progressive (by western standards) philosophy. Given the history of Arcanis and how the people of Canceri have suffered, been neglected and abused when they were a territory of the Coryani Empire, its easy to see how a charasmatic evil clergy and the Dark Prophet could play upon the disillusionment of these people, incite rebellion, and establish a functional evil society. My beef with most other campaign world's evil cultures and kingdoms is that they aren't compelling or plausible- there is no backstory or reason for them being evil other than a few evil people in charge, and people are not evil for the sake of being evil.