Hmm...
Well, I'm primarily Benjamin, of course.
I use iLiger and stripeymaney on some services, where my proper name isn't available to me.
Other nicks I've used for past characters of mine include Simba, King_Simba, Timbavati, Ithabise, Kopje, Skullcrusher...
That's about it, I think. I try to stick to my main name as much as possible these days.
Benjamin