I usually try to Role Play spreading an evil empire.. Via early slavery, theocracy, vasselage, to police state with pyramids if Im lucky to get it, and then I beeline for fascism :O
I too enjoy the empire wide whipping strategy, it actually speeds up both production and unhappiness in my empire and the world, both of which I try to maximize.. I also go for statue of Zeus to make the opponent dually miserable! When I have vassalized my neighbours I generally force them to adopt despotism and slavery to keep them down, and then when I get nukes, I make silly demands so we go to war, then I nuke them and raze their cities!
I felt this way was the most realistic.