With a few Civ Rev 2 threads that have come up recently, I thought of tossing around a few bonus ideas that could (hypothetically) make their way in.
If the response if favorable, I'll try to post a new one every week or so.
For the question, keep in mind that it is the best bonus to include in the game. Not necessarily the strongest. The broken USA rush bonus is just as bad as the 50% caravan gold "bonus".
I'll also mention if the bonus is geared towards a specific civ, or just a general bonus.