This question is a biggy. The real answer is that the rest of the world, just like Americans, has a range of opinions from extremely supportive to extremely critical. A lot will depend on the Americans that you have come into contact with (if any).
It is true that there are certain stereotypes for Americans, that are probably true in some cases but not as widely as people think.
So lets look what is behind these :-
1) America is the largest world power and affects everybody else in the world. Naturally, this is resented by many. This leads to charges that Americans are too arrogant and full of their own importance.
2) The standard American annual holiday is much shorter than that in Europe (and many other places). This, added to the fact that America is a very large & diverse country, means that many never travel outside it's borders (except in the army). As a result, many feel that Americans are somewhat insular in their outlook.
3. American forces have abroad have been rather well paid in relation to the communities they have been living in. This has caused a certain amount of friction in the past that has not always been helped by the fact that many GI's were not always the best ambassadors for the US. In WWII the common complaint about GI's was that they were "overpaid, oversexed & over here".
4. Many of the Americans that are able to travel tend to be quite wealthy and have a reputation of feeling that their behaviour does not matter if they have sufficient money to buy what they want.
I know that this all makes me sound very anti-American, which I am not. I have many American friends (both here in Germany and in the States) that I know to be very different to this. I also know that there are huge numbers of Americans that we never see that are not at all wealthy.
What I do think is there is a fine line between pride and arrogance and sometimes it does seem as if this is crossed.
Stereotypes always have some foundation in truth but are more accurate in exception than the rule.
Of course, having a leader like GWB does not help - but there are many other countries where the citizens can have similar doubts about their leader.
Supplement from 07/09/2008 03:13pm:
I have to agree with Siasl about the fact that the Americans that I have dealings with may not be an accurate sample set. Although I do not work for an American company, I do have almost daily contact with a supplier company in the States and a weekly conference call. These people are always pleasant, courteous and intelligent - but you would expect this as they professional technicians.
I should have added that you should never be ashamed of your nationality because of the way others behave. Reasonable people will judge you by what you are and you have the change of being a good ambassador to add new facets to peoples opinions of Americans.