Good summary: This article sums up some of the comments that annoy me too, but not because the comments is wrong or inherently annoying, but because the comment is simply incomplete. For example, "Correlation is not causation" is one of my more favourite sayings, but one should explain what was wrong in that case too.

I, also, get annoyed with comments that are far too long for the point being made - go write an article in response if you want. Expletives are also a no go.