Belgians, hands down !!!
While working at POP Village, we had weekly arrivals from Canada, US, England, Germany, Belgium among others. My experience was the Belgiums were the most relaxed, most appreciative, and in general, the sweetest people. These people have had to learn 3 languages right off the get go because of the location of their country so they are very adaptable. They are extremely polite as well. Next inline I would have to say the Brits were full of life and fun to be around. Then there was a toss up between the Americans and Canadians. American midwesterners would top the Americans and west coast Canadians and east coast Canadians were the better of all Canadians. Germans would be next and French Canadians would be at he bottom of the list.
With having said that, do not jump all over me if you feel offended. I am basing my opinion on my own experience. The reasoning for French Canadians at the bottom was I saw way too many times the Dominican waiters being treated like dirt by them. One time a lady demanded the waiter to speak French to her, not English, when he replied that he didn't know enough French she went on a tyrant. She came up to me and spoke to me in French, when I said I did not understand, she said "what kind of Canadian are you, you are dirt!! Then, the waiter, who I thought was very bold, said "Tell me, when I come to Quebec, will you speak to me in Spanish then!!!!
So, that and many other experiences lead me to these conclusions.
Marlie