I've run into an alternative to the classic question:

What was your most painful piercing?

I loooooove answering that question. My usual response is "Well, probably the time that I had a girl run a 4ga shark hook through the flesh of my back, but she went too deep with it, and it snagged, so she had to keep pushing and re-align it until it came back through. I hung on that shark hook for over an hour. Wanna see my scar?"

Normally after that they stop asking questions. :-) If I'm in a friendly mood, I'll tell them about my guiche, and the process of getting it pierced.