Most commonly used game settings

[LDiCesare]

I agree it really depends on map size. On bigger maps, settings with lots of money, clams of pearls, make the game tedious. On small maps, they are useful.
End game diversity is also a mod that gets some use. I'm playing a game with zero water province, and the vanilla version of water gives you very little to do (except clams, which aren't taht useful in a four-player 60 provinces game).

[JonBrave]

In answer to the OP, I think the single most important setting is screen resolution. I use 1280 x 1024.

[sector24]

I typically play on a small random map with the maximum # of AI opponents for that age. Things get ugly pretty quickly and I quit when I take 5 capitals, or 25% of the provinces, or I just know I've won but don't want to take the time to prove it. That's usually the point in the game where you are putting up globals and making SCs anyway so it's not like the AI could compete with you at that point.