Currently, some of my friends have taken to calling me 'Gruk.' (Or, in one case, Kruk, which is Dutch for 'stool') (A roleplaying character; Dwarf with a very big hammer.) Others call me Kritcha. (Again; after introducing a character with a pet called Kritcha.)
Wolfy is one others use...
But the most persistant one is Stir, a spin-off from Stirgid, again a roleplaying character.
In high school, most people knew me as Red Roofdevil. (Rooie Dakduivel.) Because of my red hairs, and, of course, the temper that goes with it.
There's one guy who insists on calling me 'dude' and 'hun,' depending on the situation, and may call me both in the very same conversation.