In the US I lived in the part of the country considered to be more friendly to their neighbors, though the exception is if you are not white, straight, and Christian. People will occasionally wave at strangers and help people who are having car trouble on the side of the road. The polar opposite can be found in China where there are stories of drivers hitting pedestrians and then running them over until they die or ignoring people on the street because they fear getting sued. In Taiwan I have found the exact opposite.
In my experience, Taiwanese have been incredibly friendly and welcoming. I have been invited to eat and drink with strangers on the street. I have made friends with Taiwanese who I consider some of the nicest people I have ever met. When I have a problem and the person can’t speak English, they will go out of their way to find someone who can.
I have only had one negative experience here so far. I was leaving Lola’s with my friend, when a drunken Taiwanese started bitching about foreigners coming here and getting a Taiwanese girlfriend. Unfortunately I did not use the opportunity to use some of the Taiwanese curse words I have learned.
Taiwan has been incredibly foreigner friendly in my experience, whether this is the case for Taiwanese towards other Taiwanese, I can not say. I have been told that southern Taiwan is more friendly than northern Taiwan but I have not spent much time in the north to really know if that is true.