I stole this thought directly from Exapno Mapcase.
In preparation for the construction of an upcoming poll, please state some specific SDMB conventions, memes, expressions, in-jokes, styles of posting, etc. that you find annoying.
Some examples:
Unnecessary spoilers
Zombie jokes in zombie threads
“Pwned”
Bad puns
“Get off of my lawn”
Referring to spouse as “Mrs.(username)”
Signing each post with your initials (:D)
Once I get enough, I shall erect my pole.
err…poll.
mmm
“Hi, Opal”
“I can’t believe no one mentioned ______” without doing a quick search in the thread (bonus points for if the OP mentioned it).
“Poll: Poll:”
Plus assorted cuteness from Day 2 after The Flood.
“A quick Google search would have revealed…”
“Band name”
Hackneyed jokes (“Hi, Opal”), particularly when used incorrectly.
Welcome threads with jokes about squids, goats etc. make me cringe.
Single-issue dopers - mention, e.g. Israel/Palestine, and you know exactly who will be there within two posts, dominating proceedings and dismissing all other opinion.
People with no sense of irony failing to get very obvious jokes.
Unimaginative and unoriginal attempts at humour.
Unnecessary signoffs.
Why the hell am I still here!? 
There’s more:
Telling anyone with any kind of relationship speedbump to DTMFA.
Deliberate nitpicking of semantics to avoid addressing the actual issues.
All the rest of you.
I’ll go with #7.
This scenario:
OP: I hate it when people do
Poster: ! 
I’m going to add “using made up acronyms and not explaining them” to the list. 
+1 ftw
This scenario:
OP: I hate it when people do
Poster: !
Edit: Anyone who quotes this and attempts to make this joke out of this post is a true lackwit.
10 posts and nobody’s mentioned:
“x number of posts and nobody’s mentioned…”
Mis-spelled words in an OP.
You are correct, and I did this in post #11. I apologise.
The term “woo.” I know it doesn’t originate here, but it’s nails on a chalkboard for me.
Re: Opal. The following only somewhat annoys me:
The following is way more annoying because it’s excessive
Let me Google that for you.
Indeed.
My biggest annoyance is for a Board that prides itself on fighting ignorance, etc., I find a lot of hostility towards anyone with an “unauthorized” worldview or position on an issue. Thus, there’s not a whole hell of a lot of variety on here as far as posters go. Those who are different seem to either get shouted down and/or driven away before anyone learns anything new or gets exposed to something that doesn’t jive with the way they see things. I suspect a lot of people lurk simply because it’s not worth the hassle to post.
People that start an IMHO thread and say in post #1…“poll to follow”.
Then probably in post #3 the OP posts again, “Damn, couldn’t get the poll thingie to work. Can a moderator help me out?”
Oooh! I’m adding “thinking anything somebody has heard out on SDMB and then out in the real world must therefore have originated at the SDMB.”