Hereditary Rule- I use it almost every single game, unless I build the pyramids.
The other three have their place (some more so than others), but they are less versatile.
If running CE, Universal Suffrage is great (more cottages, more hammers, and more potential gold to buy with, if desperate).
If running SE, Representation is great (lots of scientists=lots of beakers, and happiness where needed)
For Hybrid, I generally go for Representation as its benefits are more don't require as much specialization.
Police State is a one trick pony. I hate to use it, but in a long drawn out war (which generally means it was initiated by the enemy) I may need to switch, primarily due to WW. If I am fighting on my terms I would prefer the bonus hammers and ability to buy units to the +25% production, as cities normally either have enough production already, or little enough that +25% is pretty much pointless (compared to what a cottaged city gets +25% from forge in US).
As already stated though, Spiritual civs (or the Christo Redentor) is great, constantly changing civics can work out quite well.