I wanted not to read it and avoided it for quite some time but as it kept popping up eventually I just had to read. And retch.
http://www.lpsg.org/63000-cum-jar.html
My biggest annoyance has been with the "Ask" threads for both their lack of worthwhile content and the sheer volume of them which flooded the board with their vapid nature.
There were the "Ask a (insert your distinctness here) anything" threads. I just don't understand how anyone thinks that they, or their views should be represented as accurate of an entire group nor do I understand why anyone asking questions in those threads thinks the answers have any value for the same reason.
There were also the "Ask me (as an individual)" threads which made more sense but still contained an attention whore/talk show guest quality. If anyone really thought the minutiae of your life was worth knowing why wouldn't they PM you about it? The only one of these that got a pass wasn't started by the subject of the thread.
Precious few of the "Ask" thread weren't annoying. There were threads mocking the ask threads, though those too became irritating as they also became a plague of copycatting. Two that struck me as being worth the pixels were ones that were openly of ficticious characters answering questions.
For so many reasons the "Ask" threads win most annoying, hands down, for me.