Ahriman
Tyrant
Rise of Mankind has it for sure... only way I play Civ nowadays.
Instead of a size 1 city without buildings, a pioneer builds like a size 3 city with several of the cheap but required buildings that citizens of that age would probably demand.
I think the rise of mankind system is the best; 3 tiers of settlers, later settlers are expensive but start with larger core pop and many buildings already constructed.
Mechanics like this make colonization *much* more workable. It takes far too long in vanilla for a new world colony to get to the point where it is actually economically significant.
I agree that conquering a city destroys too much; it means that losing a city, even if you reconquer it next turn, is just far too significant.. It would be cool if we could keep most of the buildings inside a city when we conquer it.
However, there are some serious gameplay issues at stake here.
If conquered cities keep more of their buildings, then:
a) Conquest becomes even *more* powerful as a strategy, because the spoils of war are larger
b) Low culture becomes less important, because the conquered city retains all its culture-producing buildings and so immediately starts producing large culture amounts of the conquerer's nationality.
Most of the build loss is happening because every culture building gets destroyed 100% chance.
Hopefully a new culture system (especially one that moved to empire-wide culture rather than city-wide culture) will make b) less important, so we could keep many more of the culture-producing buildings after conquest.