Get some original names!

[Sirion]

My first nickname in the internet was as cliché as Assassin. But I was just a retarded 10 years-older by then. I took Sirion from the main river in Beleriand from the book The Silmarillion. Maybe not quite original or criative, but it usually works. I don't see other people using it and it's not something you can imediately relate to.
I've had trouble signing up in some sites with that name, though. When I tried to create my character in Lord of the Rings Online, it was hell to get something ressembling Sirion that wasn't already taken. Obviously someone already had taken that name. Or the game blocked it because it was a location name (even if it didn't exist long before The Lord of the Rings).

Anyway, what I usually see, at least among my steam friends, is fooling around with their own nicknames. It's often funny and creative. But I saw once a guy in TF2 stealing my friend's "nickname", that was actually his family name.