According to a "a survey of 1,500 European hotel managers conducted in April for Expedia.com" Americans are the best tippers. full article.

From the article:

Americans are the best tippers at Euro hotels, by far, the survey says. Also good at spreading around the pounds and euros -- Russians and Japanese. Least generous tippers: Germans, French, Israelis.

Americans also are considered the third most polite hotel guests, behind Japanese and British travelers.

Least polite, according to the survey: Russians, followed by Israelis and the French.

Who's best dressed: Italians, ahead of the French and Spanish.

Worst dressed: Oh dear. It's Americans, by far, followed by Brits and Germans. Maybe it's time to ditch the tell-tale baseball caps, baggy shorts, running shoes and T shirts.

And noisiest: Americans again, behind Italians.