Well, from what I saw while visiting London (and yes, I realise this limits my view of the UK supremely) people were not Americanised at all. In fact, if anything, they were anti-American. I saw an American flag lying on the ground in Portobello Road and I was treated unkindly by quite a few Londoners once they heard my accent. Perhaps your society is Americanised, but generally Americans are a little more friendly than Londoners are, at least
I'd say the people of the Netherlands are most "American" if anything.