I think San Antonio, Texas.
Borrowed from a story in the under listed website.
The story goes thus:
Recently, my wife had a flat tire and while she was on the phone calling me, a kind man pulled over and changed her tire quickly, refused her offer of payment, and tipped his hat, wishing her a good day. And a few months ago, my wife and I were trying to move a large chair into our home, with much difficulty, and someone driving by stopped, jumped out, grabbed a side, helped us cheerfully, and after a short, energetic conversation, jumped back in his car and we never saw him again. In San Antonio, many times when you walk into a chain convenience store, it still feels a little like stepping into the corner gas station where our friends are behind the counter and down every aisle.” — Danny Thompson, San Antonio real estate broker