A colossal thread from 2000. The still-actives appear to be Ukulele Ike, tomndebb, and KCB615.
Here’s mine:
Looks like I was all about the RO, with a particularly angsty OP to boot. I’m surprised I didn’t faint while writing that. :dubious:
There were at least four people posting that are still active, one that has died (RIP, Opal) and another I could’ve sworn was banned, but apparently not. What’s so interesting to me is to see names of once prolific members who stopped posting for whatever reason, but apparently still read here. I mean, like the last time they had anything was '06, yet they were here yesterday. We need a thread to get them to de-lurk and maybe tell us why.
My first topic was the Firesign Theatre: Don't Crush That Dwarf... - Miscellaneous and Personal Stuff I Must Share - Straight Dope Message Board
I’ve only been here since 2010 and my posting average is just 1.2 posts per day so I doubt that anyone here recognizes me but here goes…
My first thread:Calling 911 from an unregistered cell phone? garnered just one, correct response. The second one:** Fencepost problem or ‘off by one error’ raises its ugly head in poker** did better.
Here’s my first thread from back in 2001 http://boards.straightdope.com/sdmb/showthread.php?t=91533 and I believe Squink, scr4 and ftg are still active posters after all those years.
Not the most auspicious beginning for me on the Boards. Foreign service exam (yank sd'ers only) - Miscellaneous and Personal Stuff I Must Share - Straight Dope Message Board
Posted in General Questions on July 19, 2004: How long does it take the newly blind to develop an unfocused stare?
Only two other posters, both still active: MLS and Boyo Jim.
(I never did get an answer…)
Ossuary of James, brother of Jesus found… maybe - Nov. 6, 2002.
Only 13 posters participated, but half are still active:
Bosda Di’Chi of Tricor
CalMeacham
Revtim
rocking chair
Pabitel
NurseCarmen (last active in August)
Diceman (last active in July)
Formerly high profile posters in that thread included Arnold Winkelried and Tuckerfan. Tuckerfan’s CP doesn’t list a ‘last active’ date but I remember him leaving, though not exactly when.
Mine was a fairly stupid question about making CDs that got replies from three helpful dopers back in November 2005. Mangetout and **Thudlow Boink **are still quite active. c_goat’s last activity was a couple of years ago.
Mine was in an atheism thread from August 2002. Mangetout, Dangerosa and LHoD all were in it. Some lost Dopers were in it too. Only two posters have been banned, which seems kind of low.
Bolding mine.
If I can’t find it, how can I link to it? Fix your thread title, IT. 
Of my first year’s threads, I get into 2000 before IkeWitt shows up as a poster on one that I didn’t originate. A little later in 2000, samclem comments on one of my posts.
Lotsa lotsa names I haven’t seen for… a long time.
Not a particularly buzzy thread, but a few who responded are still around.
This is my first one. A spelling thread. Who woulda thunk? 
My first thread was about domestication. John Mace, SnakesCatLady, Blake and Hello Again all replied and all are active now with the exception of SCL, I believe.
Mine was asking about the meaning of the man who sold the world by David Bowie in July 2003. Not many replies, folks still active are emmaliminal and xash(though he just moved the thread). It did get re-animated in 2011 which was kind of cool.
Wasn’t really that long ago, and all 4 respondents are still around active on the board today.
Highfive!! You never answered me but I managed not to kill any cell phones in the 11 years since.
My first thread was shortly after 9/11 and it was aboutgiving blood in response to 9/11. I had just joined a month prior.
Just 5 replies - two from current active members friedo and bibliophage. Two from no-longer-active members I recognize Duck Duck Goose and Dijon Warlock. Then one from a guy who hasn’t posted since December of that year.
My first was one calling on Bush to concede the 2000 election. Sam Stone is still here, RickJay, Stoid (I think she was stoidela then). I don’t think wring or jshore post here anymore. Guinastasia remains as much of a board icon as ever.
“Time flies like an arrow, but fruit flies like a banana.”
Regards,
Shodan
wow.
My first is here:
Of whom two are quite active, one is semi-active, and the rest havent posted in years. Surprising none have been banned.