Pushy, ignorant, reactionary, racist, isolationist, nationalist. Stick our noses into the matters of other countries where we don't belong. Assume everything is centered around us. War/military happy. Arrogant. Loud.

Not sure if I'm missing any, but these are the prevailing things I see when people are talking about the US and the people who live here.

What is hard is that there are of course people (many people, even) that match one or multiple of those descriptions. But the same as it is silly to generalize all of Europe (or even any one European country), it is silly to generalize all Americans.