Perhaps this suggestion clashes too much with the fundamentals of the Civ series, but I think food resources need to be completely reworked. It never made sense to me why corn, for example, exists on one grassland tile but not another one right next to it. In the real world, once new crops are discovered they can be grown anywhere that the climate and soil permits. My proposal is that food resources can be farmed on any tile with suitable terrain. For example, wheat farms could only be created on flat plains or flood plains tiles. Grape vineyards could only be created on plains or grassland hills, and so on and so forth. If we really wanted to get complex, latitude could be incorporated to add climate as a factor, that way a grassland tile near the top of the map gives different crop yields than a grassland tile near the equator. Also, generic farms would be removed from the game completely - an empty tile can only be forged for its basic resources (like game and wild berries and nuts). Now you might argue that giving all players access to these resources removes the bonus of having them, but I also think this would make the game more fair. Players would then focus on building cities in good terrain near fresh water as opposed to rushing to found a city in an exact spot with the best fat X city radius. In the real world, things like fish and corn are ubiquitous. Wars should be fought over strategic resources (oil, iron, etc) and fertile land, and not over whose city radius covers the coveted +2F Banana tile.