I like the americans because of the workers go faster, so then you can have more commerce which means faster building of units and wonders. The expansionst part is good in the begeninig because you get about 4 techs off the goody huts and u meet other civs faster and you can conquer their capital in the begining because of the poorly defended cities. If u can survive until the industrious and modern era then u r gonna win for sure.