I want you to note that Entropy, who started this, is *not* American.
However, if you want the American perspective:
There is insufficient difference between the British, the Irish, and the Scottish for them to be acknowledged as any different. They must all be the same snobbish elves. You elves may differentiate, but a pointy ear's a pointy ear.
Americans are human, because, well, we're human (and better!).
Canadians are therefore half-elf, because they live near us and use our TV, but they think they're British (fools)
D&D gnomes are more tinkerers than dwarves (who mine), so yeah, I'm going with most of the far east. After all, we can't tell them apart, so they must all be the same.
Russia, our on-again, off-again ally/enemy are dwarves. Because, again, they drink. Also, their stoic, stubborn, and we don't understand them (nor do we probably want to.)
I'm going to put Germans as half orcs, just cuz we have a better memory of WWII than anything else that's ever happened in history.
Africans are halflings, because we more or less ignore anything about Africa, including our own citizens.
As I said before, the Middle East is populated entirely by goblins and kobolds. Because they're warlike but we find it so easy to convince ourselves to kick their trash around a bit (and also easy to execute said kicking).
Which means that South America and the rest of Europe are various orcs, hobgoblins, etc. There are enough "evil" humanoid races that we really don't care about making any distinctions.
You Australians must be fairys. Not because of any "gay" thing. But because your country is supposed to be cool but I don't know if any of us really believe in it.