Expansionist
Pretty short term bonusses. A scout at first won't matter all that much. And extra stuff from goody huts is only useful early in the game
Militaristic
military buildings won't be all that plentyful, and you only pay less for building them, not for upkeep. not that special either. and the promotion bonus is only good if you play agressively, which I don't.
Religious
same as above. only building, not upkeep. And I don't think I'll switch govs that often.
Scientific
Same as above. But you do get a free tech once in a while. Still I prefer Commerce and Industry.
Commercial
quick trade boost early in the game. low corruption+extra trade in city square means big empires with lots of cities recieve more bonusses. exactly my style
Industrial
extra production kicks ass. and faster workers too. Finally settlers that work fast.