The ones where the OP is worried that their 790 in SAT II Math is a low score and will hurt their chances at whatever schools they are applying to.
And, of course, the chances threads. Those annoying because they are all complete speculation. I agree that the complaining about 2300+ SATs is irritating - there is a lot of humblebragging on this site.
Threads where OP’s parents have over a 100k saved but want FA bcs they want to spend the cash on something else.
Even better is when the OP and his parents are international and think an American college is going to pay for everything despite their giant assets.
My least favorite threads are:
Next on the list are the ones who ask the same question answered in the thread directly below or on the first 2 pages of that college’s forum. This is the mother-bleeping internet, the thing that makes checking for answers so much easier than word-of-mouth and going to the library to look at reference books. And you can’t bleeping bother to read 10 or 30 lines of text. My dislike of these threads is more about the way these posters take advantage of people who try to contribute, who try to be helpful, with the expectation that doing so little work will be rewarded as if the person taking the time to answer has no value. This is a problem on the entire internet, which is why “let me google that for you” became a meme. I sometimes miss the old days - not really - where discussion groups would tear people apart for not doing the basic research of reading threads and a quick search before asking newbie questions. That was brutal and I don’t really miss it because, bluntly, even brutality didn’t work to get people to care enough about your time to do any work at all.
The ones where everyone just can’t get it through their heads I’m right.
ETA - about everything.
Threads about plans to gain instate residency for tuition - NOT going to happen!
The chance me threads - I stay far, far away because they drive me nuts. And the posts of “I have a 2400 on my SAT, 4.0 GPA, cured cancer, etc., etc., etc.” I think someone called it humble bragging?
The ones where certain posters waste space and others’ time by repeatedly posting “Great post!” to others who we all know are already part of the same cabal. That is what the “Like” button is for.
LOL
@OHMomof2 The comparative form of gram, what’s the big deal?
@agoodfloridian - grammest gram ever!
Threads from Oxford rejects who think need-blind Ivy League schools in the U.S. will give them FA because their £300k income parents w £millions in assets have an expensive mortgage & private school bills.
Any thread with the word “prestige”.
I think I’ve posted this before, but all the obvious clickbait threads.
Though it’s hilarious that the majority fail.
Threads where posters answer a definitive response that is in direct contrast to the responses from everyone else on the thread, because they have not read the first post carefully! And then when other posters attempt to clarify why this response does not fit the OP’s question, said poster adamantly argues their point!
Reading comprehension 101.
There is a rather pointless (at least to me) thread going on right now about some kid “shotgunning” his college admissions. People just seem to be going around and around on the same type of responses.
Threads where someone feels the need to illustrate every point they make with history lectures.
…or stories about their cousins, ex-classmates, etc.
…sometimes both in the same post. 
There was a thread on here with some American Indian student with a 1300 SAT (and I don’t mean CR+M, I mean total) wanting chances for HYPS, etc. That thread got REALLY ugly REALLY fast. One poster threatened the OP should he get in, others made remarks about his race and admissions, etc. That thread got removed within minutes of it being posted.