I can vouch for Canada's reputation.
I've been fortunate enough to travel to both the US and Canada, and have been welcomed by very polite people every time. But back home in the UK where people haven't had that opportunity?
Very cold towards Americans. The opposite goes for Canadians. Viewed as a lot friendlier. Of course, there is good and bad everywhere.
and I'll agree with this.. Every Canadian I've met has been pretty friendly. Even Brit. I frequent Vegas and each time meet people from Canada and England. The difference is a breath of fresh air. Never met someone that wasn't friendly from either country.