I had just finished reading the first of the Steven Brust Vlad Taltos stories and just read Dracula. So when I got to UCSC and was told to pick a login I chose Cthulhu. That was taken so I chose Vlad.
When I left UCSC I lost the use of loging in as vlad, but I still used the forum services remotely, so I chose the name deadvlad.
SCO gave me this one. I worked for them for 10 years and there was never another jason there in all that time, but still it was jason+a. It got so bad that when I started up my system at home I retained jasona as a login because my fingers were used to typing it. When I joined Lutris as a start up I was given "jason" and I kept it because it was a point of pride (being one of the early hires, I _deserve_ a prime name). I now regret it, as it doesn't mesh with my home system. :)
I use this one for Quake, Unreal Tournament, Mechwarrior, Starcraft or any of the online chat-enabled games. No real story behind it, I thought it sounded nice, and it means the bane of woe, how cool is that?