When I first came here, I tried to register with the name a²+b²=c², the Pythagorean theorem. However, someone already registered with that name. (Guy probably never posted…grrrrr)
What name did you want when you came here, but couldn’t get for whatever reason?
Blondie, of course!
Hey, Blondie, are you out there? Wanna sell your user ID to me, you flaxen-haired b----h? Heh.
My first choice was vanillanice.
Natch, it was available, who would want it?
Mine was Astroboy… it was taken.
I now understand what the people who were trying to patent Formulas #1 to #408 went through!
j
really
it’s too short
Aesiron.
It’s never taken.
Cecil. Someone got there first…
I’ll confess, I’ve been on this board under a couple of different names, I think, or maybe just one other (never banned, though, just forgot the password and stopped using the e-mail addresses).
TMR was the first (and I posted to this thread, years before I started the thread in IMHO).
After that, S-Terry Dan (incredibly obscure video game reference). Hey, if you’re still around Bear_Nenno, did that advice help?
Then that computer broke, and I spent two long netless years (between poverty and Air Force training). So now here I am, on my third choice of nicknames.
Since this is basically a poll, I’ll move it to IMHO for you.
Cajun Man
for the SDMB
The first time that I registered at any message board, I assumed that I would just use my first name and last initial, Alex P. However, I noticed that the board already had an Alex, an alex, an Alex b, and an Alex T. Consequently, I chose ITR Champion for that and all subsequent registrations, including this one.
I originally tried to be Bear, which is what my friends call me. (Short for Barry)
Then I tried to be Papa Bear which is what the grandkids call me.
Couldn’t do that either.
Just as well, as a certain class of people, (you know who you are) have pre-empted the name ‘Bear’ for their own nefarious purposes.
Then I tried Pogo, from the comic strip. Already taken.
Then I tried Bewitched, Bothered, and Bemildewed - the three bats from the Pogo strip. Wouldn’t work, too long I guess.
Then I decided to get really obscure and tried Bumbazine, from the comic strip ‘Bumbazine and Albert the Alligator’, Walt Kelly’s first strip, which evolved into Pogo.
That one stuck.
Back in the days of the local BBS’s, I went by Maverick. No, not from the Top Gun movie, but from the James Garner, Jodi Foster, Mel Gibson movie Maverick. It was fun for a while because I there were a whole bunch of people who that that was my real name. To my good friends and family, I was Joel, and to most of the people at the BBS get togethers, or the people I played Magic the Gathering with, I was Maverick. But after a while, I got tired of it and just went by my real name.
Monday of this week (3/8) I got tired of just using my boring old name, and tried to bring my old user name out of retirement, but TubaDiva informed me that somebody else is already using that name 
Oh well, I checked and it appears that nobody is using the name Tron, so I’m trying for that now <crosses fingers>.
Should read
I origionally considered con quesa as a username. In fact, I use it on another board.
Before this place, when I wasted loads of time on Compuserve, I was Lady X .
I loved that name, but it tended to attract alot of s/f? and after about 3x that gets tedious. I am a hermaphroditic married norwegian gorilla, in case you are wondering.
When I signed on here, I was ja1166 but that was so unimaginative it practically cured insomnia.
Somehow, through the Gods and Goddesses of the Web, I was inspired to instead of putting Lady X in as my name change, but at the very last second in a moment of pure clarity, where the rightness of the Universe proved itself to me , my current user name came to me.
And I haven’t stopped blathering since.
Kat was actually my first choice for username, and this is one of very few places where it was not already used (probably because I got in on the ground floor, so to speak).
I have been considering changing it, though.
Urban Ranger
It’s got a nice irony to it.
My original username was my real name, but I changed it due to anonymity concerns. Some things I post here I would like partially obscured from friends and family who read the board.
As a Dvorak fan, I wanted AOEU to be my username.
Sadly, it was taken, so I settled for HTNS.
I first registered way back in 1999 and posted probably twenty times or less. Then I went away for a couple of years - and when I came back I couldn’t remember my original username or under which of my myriad of seldom-used email addresses I had registered.
The second time around I couldn’t think of anything original and creative (I tried to come up with something along the lines of Shirley Ujest, Satisfying Andy Licious, et al) and all of my real-life nicknames were already taken, so I used the name/nickname of a character from a book I was reading at the time.