Keep in mind that many European and most emerging or industrializing nations see America as a competitor in the world market, and vie with us for- well, sometimes no more than international influence (France). Anti-Americanism is a powerful propaganda tool and you'll see the evidence of this when you talk to people abroad.
As an aside, nothing would make me happier than more cooperation between the UK, US, and Canada. Our three nations have a shared heritage and unique world view. I do wish the US government would pay more attention to our allies. I'd like to think I can always count on you, but I know our government has been dropping the ball.
Trivun, I disagree that we owe you anything, though. And I'm surprised you say we forget about that connection, because I haven't experienced that. Many Americans celebrate Jamestown, VA as the first city in America, even though that honor indisputably belongs to Saint Augustine, a Spanish settlement. Also, I disagree about the world wars. To me, WWII is the one that's debatable. We had a clear shared interest in that conflict, but in WWI that wasn't as clearly present. And you guys begged us to come. I can't imagine any basis for claiming that you saved us- that wasn't even our continent. But I still think Britain is, and should be, our best friend in the world.