I was in Nashville over the weekend and had Christmas dinner at the Opryland Hotel. Having lived in Chicago and Los Angeles, I was struck by how polite the hotel staff was...

The party line at a Ritz Carlton is "my pleasure" but they really seem to mean it. If you ask fof directions to somewhere in the hotel from an employee, they lead you there not simply offer directions.And then when you say Thanks, they come back "My pleasure"

After 2 years living in SC, I adoted the "Yes Sir, No Sir". My son will do the same.

I worked in service oriented businesses for several years, since then I use "yes sir/mam" etc... almost exclusively. It doesn't hurt and people seem to like it.

see, but you are from Texas, and that is how they are down there

In the summer time, during our short tourist season, I put in some time at the local Visitor Information Center (which also has North America's only tidal power generating plant), I often respond "My pleasure." to our guests, mostly because its the most fun I've had in a 'working' environment.
The only time I'll say "No Problem." is when someone is suggesting the service I'm providing them is too much effort.
I love summertime.
Les