Mine is probably all of the religeons from the Thief series. These include:
The Hammerites, who are basically a bunch of 7ft tall, industry loving, hammer-wielding, poetic brickshithouses.
The Mechanists, they're pretty much the same as Hammerites, except armed with maces, and backed by bomb-firing robots, that sound suspiciously like Droopy the Dog...
Lastly, the Pagans, half-naked tree huggers who worship a devil-like fellow, they like to sabotage the Hammerites and Mechanists at every oppertunity.