That's a really good question Rev. I've been thinking on it since you first posted it, without coming up with anything worth saying that somebody else didn't say first. What I've gleaned from reading this thread so far is the rather obvious conclusion that there's no simple answer beyond the trivial: an American is a citizen of the United States of America. But that was obvious from the beginning. There are also a lot of statistical statements to be made that characterize Americans as a group, some of which are a little alarming, like the stat I heard this morning that over 60% of Americans get their news almost exclusively from Fox, and believe it, which certainly explains why a large percentage of them still think Sodamn Insane did have WMD, did have a viable nuclear weapons development program, and did have something to do with 911. But I don't think that kind of stuff answers the burden of your question either.
So I began thinking instead of the individual Americans I've encountered. Like a lot of thoughtful Canadians, I find it difficult not to harbour a certain degree of anti-Americanism, though that's directed at their government, not the people. I used to be able to say that all the Americans I've ever met have been good people, it's the ones I don't know that vex me, until I met the prototypical ugly American. That guy was almost a parody of everything America has been criticised for, here and elsewhere. Arrogant, ignorant, racist, imperialist, an altogether despicable human being. His message to the black community in America, for instance, was, in his own words, "conform or die." He's also the guy who told me that there's no justification for any manufacturing industry to exist in Canada, 'cause America could do it better, cheaper, faster, yada yada, and sell us anything we want.
But he was the one jerk out of hundreds of Americans I've met, and alas, there are fools everywhere. I've met Canadians like him too, and Europeans; his type is certainly not unique to America. But his type is rare: all the other Americans I've encountered, as tourists here in Regina, or as a tourist myself in the border states south of me (and I have some American relatives), have been, without exception, friendly, generous, interested, and interesting, people.
In particular, I remember the people who rescued me and my family when our car broke down (failed fuel pump) literally in the middle of nowhere in Montana on a breathlessly hot summer day 15 years ago. They arranged a tow to the dealer (Cranky Ranky's Midland Dodge; does that inspire confidence?) in Billings 100 miles away, where they were headed as well, they followed the tow truck with us, they took us to a couple of motels and would not leave us until they were sure we had a place to stay, and they came back the next day to check up on us, to be sure we were getting the services we needed before heading back home to Roundup (yes, that's a real place in Montana).
Those are the people I try to remember when I think of Americans. I've seen some of the best of them, and some of the worst, but the good people far outnumber the bad, by at least 100 to 1. I'm not impressed by the current American government, I'd characterize them as fascist assholes, and very bad things have happened to the American psyche since 911, but I choose to believe, based on my personal experience, that the average American is a kind, generous, good-hearted person who'll go far out of the way to lend you a hand. That's my experience of them.