Tom decided he'd call me "kid" like the second day I had my town, and it's spread like crazy since. I also have "tacker" for Sylvia (Australian slang for kid) to stick with the theme. I might give Muffy a unique one, too. Otherwise, I'm happy with everyone calling me kid, assuming a better nickname doesn't start making the rounds.
"Senpai" and/or "my liege", lol. But Cyrano calls me "june bug" since I agreed when he asked to call me that. One time, Tangy suggested calling me "Sugar D" and I had Dizzy before I reset my town and he asked to call me, "Wonder D"