Living in Canada a lot of our culture is similar or identical to yours. It is hard to make broad generalizations about Americans due to our closeness with them. While there are more than enough stereotypes in the media about Americans many of them are hard to believe because of personal experience. Living in a city that is less than a two hour drive from the American border you have a lot of exposure with the American culture (on a personal basis).

While Canada and America have many differences government wise, culture wise, and sometimes even humour wise, we have many things in common. Being next door neighbors your culture rubs off on us quite often. However, that being said it can seem that these differences have made Canadians more proud to be Canadian. Much of the Canadian culture is defended with fierce pride - sometimes to the point where any difference from America is a good thing (and yes, this may be seen as a fear of being overshadowed). However, politically wise much of Canada remains different. Some obvious examples of these differences would include national healthcare vs. privatization, the Canadian immigration policy of a "cultural mosaic" vs. the American "melting pot", or Canada's foreign policy of peacekeeping vs. America's foreign policy.

Quite often the two nations can't be compared. For example, our crime rate cannot be compared because we are one tenth the size of America population wise. This, of course, does not stop the comparisons.

Growing up in Canada many of our differences from Americans are highlighted while many of our similarities are seen on a day-to-day basis (or rather while visiting the other country). For the most part Canadians and Americans have gotten along well.

That all being said, there are some parts of America that I personally do not agree with, mainly, as someone has already mentioned, America's imperialism.
Many of the other differences, do make me proud to be Canadian, but they do not lessen my opinions of the American population. (The biggest change I would like to see in America would be some in their perspective of other countries.) Many of the problems in America are highlighted because, yes, America is the world's leading power and is criticized thusly. It would be nice to see some foreign policies change with the upcoming election (and no I'm not just talking about the war in the middle east) but I also hope that a lot of the political attention will be focused more at home, improving the standard of living.

It is hard to judge a culture you share so much with but it is not hard to form wrong opinions due to America's media spotlight. The best thing is to maintain an open-mind and to not assume too quickly.