When I made my first AOL account (with my parents hovering over my shoulder), I made it the nickname my sister called me (for being weird) oddjobbob, with 705 tacked to the end as my birthday.
I used that for about 5-6 years, until I changed it to Bobbeh (Bobby with an EH instead, god i'm clever) on this Naruto forum I used to frequent.
I got Xbox Live about 1-2 years later, and made it Bobbeh705, since Bobbeh was already taken. After about a year of that, I got pretty bored of the name, so wanting something creative, I decided to go as 'effeminate' as I possibly could, and ended up with Unic0rnSunshine.
I stuck with it for about 3 years, shortening it to Unic0rn at some point.
Since then, I've gone to just Bobby, considering that's all anyone called me anyway, just a matter of not confusing people.
The only issue is that there are other Bobby's in the community already, so I may have to change it again. *_*