I normally like to buy my players from the major footballing nations such as Brazil,Argentina,England,Germany,Spain,Italy,Franc e,Portugal,Netherlands...
Now and again I may go for other south american like Colombia or Chile, Also from Europe I've had Romanian players in my early days as well as Turkish and Scottish players, From Asia I choose South Korea or Japan, Africa it would be Ghana, Nigeria, Egypt or South Africa and from North America its usually USA or Mexico and also lets not forget Australia from the Oceania continent.
But in reality, It doesn't matter where they come from because you can change nationality and player names for 1 token each.