Very hefty request. This game is a great game for the reason that everything in it can generate pages and pages of discussion on its pros and cons. Check the threads here. Single nations have generated pages, much less trying to discuss all 17 of them, AND the various theme which can add half a dozen completely new set of pros and cons to a nation.
I dont mean to put you off but any answer is likely to generate a flood of different answers. If you dont mind a suggestion Id say try playing them all. Seriously. Have fun discovering little advantages and disadvantages. If anything seems to be either "automatically good" or "automatically a rotten choice" then come back and ask about it. those are fun discussions.
