I had a great one just last week. I went to a Forest Service ranger station to pick up a permit, and the young ranger on duty did a double-take when she saw my birth name on the computer screen. But she recovered nicely, and said "Oh... (X) is an unusual name, isn't it?" I said "Yes, and I hate it, and I'll be getting it changed in two weeks." She
got it immediately, said "Oh, what are you changing to?" I told her, and she smiled, held out her hand, and said "Pleased to meet you, (male name)!" After that she gendered me correctly, had some curiosity but wasn't the least bit intrusive or inappropriate, and -- the best part -- when she issued me the card that said I'd watched the orientation video and didn't need to see it again, I asked her if she'd put it in my soon-to-be new name, and she did!
Then I had to sign my name on the back of the card, and I realized it was the first thing I'd ever signed using the new name. That was a wonderful moment, and the whole experience made my day -- completely unexpected!
Here's a big shout-out to Miranda the forest ranger!