According to this article the French are rated the most obnoxious tourists by a survey conducted through expedia.com.
Many years ago during a power outtage that rendered the trains at a standstill I had the experience of sharing a cab into the city with some French tourists. We got to speaking and I found them rather candid and fun. They told me that everyone hates the Parisians and that they are the most obnoxious people ever. They could totally understand why our perception of the French was so horrible because they felt that way too.
So the French are known for being the least likely to try to speak the native tongue of the country they are visiting and American's are known for trying the hardest.
I've always espoused that the media is biased and messes with our perceptions and is the biggest instigator of America bashing/hating.
We American's aren't perfect and who can or needs to be, but we are the most willing to go out of our way to fit in and be kind that's for sure and it is hugely under-reported.
Well, the Japanese, Germans, British and Canadians were ranked the top-liked tourists. Americans came in 11. Not bad all things considered.