I took Senni Ti from dynasty warriors, I had a body guard called senni si at some point. From there whenever I had to make a username, it just pops into my head and I've stuck with it since.
Shortened it to Senni more recently, actually found Senni Ti unavailable in some places :O.
Pretty much as Vodner says though, if I can change my name frequently, I do
. Particularly native (stuck with * recently though) and JA.
Other Crpg char wise, most are really simple: iTurtle, iHA and iShoot (pre-STF, found i---- funny at the time). Exception being Titan_the_Peasant; wanted a name that fitted a pure STR scythe user (back when STF came out). The surprise on peoples faces when I two-hit them
.