Keep in mind SA forums hated "memes" unless you were really good at it. That made the forums great because it also involved an element of risk so if someone wasn't sure how good their stuff was they're at risk of getting banned.

A simple example: There use to be a forums poster who posted just screenshots from old NES video games that was always super relevant so he was never banned (usually if you just post a meme with nothing else in the post you'd get banned).

Another one: The whole concept of tricking users into reading a long fictional story that started one way and eventually delved into some other topic altogether. I guess you'd now call it a bait-and-switch (w /an anti-clamatic ending).

That too was started (or at least popularized) on SA. A user named, "Hakan" posted a lot of fictional stories that were pretty good and always had a twist ending. Imitators who tried to copy him but sucked were told, "You're No Hakan." Then that catchphrase became too memeish and was banned from the forums (unless again your comedic timing of the phrase was hilarious).

Edit: Even the meme of, "Read post, then read saw username <username>" meme, seems to have come from Hakan/SA which was a "meme" where you'd read a story, get tricked by it and make a post just to specifically say you were tricked. That got banned pretty quickly as well but it's so common in reddit and other parts of the internet now.