Comicmess
Comicmess is probably the oldest intellectual property I own -- I had JUST started getting into reading webcomics in the 6th grade and my mom told me I needed to set up an email for professional-related tasks. I complied and suggested the name "comicmess" because I had been reading a whole mess of comics online. I'm not sure why it was "mess" specifically, though - at the time - I did hate it when my friends would add "-ness" onto words (like "coolness" or "awesomeness"), so maybe I was subconsciously staying away from that.
The most common typo is comicness which just makes me feel uneasy.
I carried Comicmess around with me through yahoo and hotmail and gmail until I realized I could buy the domain and use it for my portfolio site. I also find the username is generally unclaimed when I join a new service or play a new game, so that's convenient!