It's "hardly scientific to make comparisons like this based on empirical observation (unless you're exceptionally slutty!).
For example, there are 69 American cocks, 18 German, 14 British and 8 Polish cocks for every 1 Irish cock in the world. (152 million American men, 40.2 million German men, 31.2 million British men, 18.5 million Polish mention : 2.2 million Irish men).
That said, Ireland invariably comes out close to the top of most global comparisons - so if Liam Neeson, Michael Fassbender and Colin Farrell's combined cock average went up against the equivalent number of American cocks - 196 - then I'd guess that Ireland would come out on top. Hell, I'd even throw mine in there in the national interest too. I'd definitely win the biggest foreskin trophy... ;o)