For me personally I think Imp is strong during the Ancient Age where you're expanding with Settlers and the Renaissance Age where you're peaking at GGs Production (about 4-5).
The other Ages inbetween and After for me is when it's weakest.
The Classical and Middle Ages where you're still accumulating XP for GGs, and the Industrial Age onwards where diminishing returns occurs for GGs.
So a cheap building during the Classical/Middle Age and a cheap building after the Renaissance Age Ends would be a nice balance I believe.
My personal choice would be cheap Stables and Airports.
I know some of you believe cheap stables would should go to Aggressive but Imperialistic is the trait we're trying to improve, and it probably needs it more then Aggressive.
Plus Airports for a nice late game boost when GGs are harder to come by (unless you play advanced start)
Cheap Jails and Custom Houses are also very nice options but they come around the time where Imp is at it's strongest in terms of GG production and it's usefulness will probably die off once you hit the industrial age and onwards.
The other Ages inbetween and After for me is when it's weakest.
The Classical and Middle Ages where you're still accumulating XP for GGs, and the Industrial Age onwards where diminishing returns occurs for GGs.
So a cheap building during the Classical/Middle Age and a cheap building after the Renaissance Age Ends would be a nice balance I believe.
My personal choice would be cheap Stables and Airports.
I know some of you believe cheap stables would should go to Aggressive but Imperialistic is the trait we're trying to improve, and it probably needs it more then Aggressive.
Plus Airports for a nice late game boost when GGs are harder to come by (unless you play advanced start)
Cheap Jails and Custom Houses are also very nice options but they come around the time where Imp is at it's strongest in terms of GG production and it's usefulness will probably die off once you hit the industrial age and onwards.