What is (are) your most used Internet ID(s) and how did you come up with it (them)?

Spadow

When I was a little kid I read the comics of Spawn and even saw the live action movie of Spawn.
I was fascinated by this character.

 Spawn

After that I met the interwebz. I learnt that an alias was required on most of the community boards and in games.
So I thought about Spawn but that's not unique since it already exists. So I removed 'wn' and added 'dow' and Spadow was born.

My very own unique alias.