When I played D2 I had a bitch of a time finding a name that was allowed, they all seemed to be taken. I said "fuck it" and just typed in Noodleface out of anger. I then played Noodleface the bowazon for glory for months. I didn't use it for awhile, but now it's the name I use in every game.
I was also Aria on fohguild's forum. That name came from my FFXI character name. I jokingly named my char Ariagiovanni after the soft-core pornstar, with no intention on keeping it. I played her for like 6 years straight. I always hated the name after I made it, but since you invested so much time in your character in that game, that was it.
Occasionally I will use the name Kishin, something about a japanese Demon.