The best experience I've had is with people in the USA. We broke down once in a small town in the middle of nowhere and the locals couldn't have been more helpful as were the hire company.
Worst experiences have been in France. We've met some pretty nice people at one extreme, but at the other we've also come across some really rude ones. So on balance, I'm afraid France loses on this one.
I've not really been to enough places to make any real comparison anyway.
I agree with Starr that the North of England's pretty good. But then I would say that, being one of them .
To be honest, it makes me uncomfortable when people are too friendly anyway. We have a friend who is very touchy-feely, because that's how she was brought up to be. Drives me nuts I'm afraid.
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Any fool can cope with a crisis. The art is in dealing with the crap you get everyday.