The board is running real slow for me right now, but there is a hilarious story by Master Wang-ka and a kitchen fire. It’s not an OP, but it was a post in a thread about kitchen horror stories.
Actually, anything by Wang-ka is a treat. I really miss him. 
I’m mainly posting this for shijinn’s post, but I had some fun going back and reading my own (and the responses). I’d forgotten about that. Guess sometimes a lollipop ain’t just a lollipop.
Anyways, the thread
I would put up a banned members thread for this list, and also inclusion in the “Ask the…” thread list. He didn’t name the thread “Ask the guy who lives in MENA about his views on Iraq, the war, et al” but it was essentially what it was all about. Over 500 posts in GD…pretty good.
I give you Collounsbury:
Lounsbury on Iraq & MENA: War, Politics, Economy & Related Questions
-Tcat
I’ve always been partial to Skyscrapers, Executives, and Miscalculated Feces .
Don’t forget auntie em’s fabulous Missing Co-Worker thread (It’s really called “OK, so my boss is reading my coworker’s email . . .,” but who ever thinks of it that way?) and its nail biting sequel Missing Coworker, Part II.
Not many people know that… Well they do now.
Or did once, for 20 minutes.
Actually they would also have known this if they’d read Bill Bryson’s A Short History of Nearly Everything
Throw another one the way of auntie em with her Ahh, the Wisdom of Toddlers (or: Auntie EM’s Big Vagina) thread.
'Course, I just might be a bit biased. 
This one and its partner thread, here. Pure culinary heaven.
(Is there a way to get all these recipes on CD or anything? I’d love to have these as reference to print off my computer when I need to cook a meal…)
I’m casting two of my votes onto the piles for The Horror of Blimps and …& BOTH OF YOU LOSE MY NUMBER!!!
Yes, yes. Second. Absolutely critical. And really, when you think of it - there must be a chili thread.
I cam in here specifically to nominate this thread. The OP is an absolute classic.
But that leads me to a couple of questions: what are the criteria people are using? Is this a quest for the best OP, or for the best thread?
Some threads start off with a very funny or touching or intelligent OP, but then devolve into little more than a series of “great OP!” posts.
Others start out with fairly mundane questions or issues, or a fairly nondescript OP, but develop into excellent conversations or debates. I think that, in judging the best thread, it’s reasonable to look beyond the OP to the thread as a whole.
This thread started by the infamous Jack Dean Tyler will be an eternal legend of the SDMB:
From the Telemarketer thread:
The bolded part is still IMO the best line I have ever seen in a reply.
[thread=283407]This thread[/thread] has to be in there somewhere. And the Scalar weapons thread has to be number one. It reached a thousand posts in GQ, and gave birth to the most popular doper catchphrase.
I second the second. I think it’s my favorite.
Well Dang! I was comin’ back in to nominate Auntie Em’s missing co-worker thread but I got beat to it. OK, anyways, let me second that one.
I also nominate Sauron’s I Stood Next To The Emporer Of The World At McDonald’s Comedy gold yet again!
I’m going to nominate Dante’s Tales of the Sweaty, Feculent Herd.
A Doper enlists our help in persuading his teenaged son to take a shower in the unforgettable Child of Filth.
The fabulous meltdown of Beryl_Mooncalf . Extra points for gratuitous colored text.