I got my villagers to start calling me KH, since, well, just look at my username and you can see why, heh. I've never been a huge fan of the nicknames they try to call you.
I made some animals call me "highness" and others call me "princess" and my character is male but it's so much fun lol. I've seen a lot of people make their villagers call them "senpai". maybe for my next trick I'll make them call me "satan".
Currently Lolly has dubbed me "S-cat" which makes me laugh uncontrollably. I couldn't deny her. It was the first time Lolly offered me a nickname.
I've been called:
Genius - Lucha
Seraphim - Kitty (Technically it's Serif's FULL name, but Kitty being the only one to use it fits her personality)
Cuppycake - Lucha again
Sweet-S - Agent S's legacy
Chica - Shari's legacy
Buddy - Thanks Lobo....
Muffin - Celia's legacy. Fitting...
Bluebear, Molly and Fauna call me blossoms (this one spread like wildfire, lol! Everyone used to call me this, but I kinda changed things around for variety.)
Whitney calls me darling.
Chief calls me dude. (sometimes I change it to gorgeous, lol!)
Marshal calls me muffin.
Erik calls me bro.
Since my town is based off of a city in X/Y (which was modeled after France), I have them call me things in french like "mon amie" and "mon cher" unless it's Felicity, then I just let her call me whatever. It's usually "Pop Star" and I think once it was "Pookie". c: