Internet latency map

Consider Keynote's

Internet Health Report
http://www.internetpulse.net/

or

The Internet Weather Map (IWM)
http://www.internetweathermap.com/

for a starting point.

Though I confess that I don't entirely understand your question. Surely you need to first understand where your customers are. For example, if your game becomes popular in Brazil (fifth most populous country in the world), you're really going to want to put a server closer to Brazil, regardless of whether you have a co-lo with good latency characteristics between Denmark and India :)

http://www.akamai.com/html/technology/dataviz1.html
An internet weather map, yes the internet has its own weather.

This site seams to give pretty good info about the whole internet.