Overall I like them, but there are a few that annoy me. I particularly hate
when it is used in response to another person's post (as opposed to a ridiculous news headline or something). It is just rude and childish.
This is the first thing I thought of when I saw the title of this thread. I don't like the rolleyes emoticon for this very reason.
Now, if you'll excuse me, I have some emoticons to steal...