I seem to recall a topic about this. If I find another one, I'll link it here. Anyways...
The history of my nickname started way back in 2003, It maybe even earlier, but at that time, I was in love with emulators and playing all of the sonic games from the genesis/megadrive, gamegear, 32x, etc... Because of this, I wanted to have a nickname based off of it. Since I suck at nicknames (And I still do :<), I decided when I was going to create an account for a MMORTS game called Shattered Galaxy, I would call myself "Sonic". It happened to be taken and I was thinking of another nickname and then I realized the next letter is "t" in "sonicthehedgehog" so I tried out "Sonict" and I have stuck with it ever since. I don't have any other alt names since I suck ass at making them.
So there is my story. AJ's story would be cool since his story is quite similar to mine without the online crap IIRC.
Tell us your story, SSNTails!