I suppose it depends on what towns in Briton you're talking about. In somewhere like Croydon the people are too in a rush to give a sh1t about their fellow man/ woman and an amount are of other nationalities anyway, but in most towns and rural villages the people still have good manners I think and I'm proud of that. This is totally unlike most of the places I've been to in Europe - Particularly France!
I also personally think that the good manners of Brits is acknowledged worldwide and is sometimes stereo-typed and laughed at in American films.