I'm going to throw in my vote against "sweetheart" by men I don't know.

This happened to me just tonight. I was out on a short run and there was a pick-up truck pulling out of a driveway. There is a lot of construction happening on my street, so the truck had a bit of manuvering to do. The guy saw that I was coming and tried to move out of the way (which I appreciated), but I had to slow down a bit, anyway. He apparently felt badly about it and apologized to me....and then tacked on "sweetheart" to the end of it.

"Sorry, sweetheart!". Grrrr.