This is mostly a silly poll just for fun. But, I'm posting it because I've encountered keepers in both areas who complain that the other region has "better" local ants. I also think that because we have so many restrictions in the US (which I've been critical of, and will keep being critical of) in the US ant keepers have dug deeper into local species.
For example there is a growing community of keepers of NA native leafcutters ... would that have happened if we could import the larger, more flashy SA species? I bet there are some hidden gems in Europe.
Comparing the US a country to Europe is a bit lopsided, but I'm thinking of this in terms of comparing two similar temperate regions.
I have "ant envy" for South Africa and Madagascar, and several parts of Asia... not leaving y'all out because I think these two are the best. Just to make that clear.