Boy, am I old. About ninety percent of the expressions posted in this thread are complete mysteries to me; never heard them, and don't really want to do so.
My hot button? "Hating on". "Hate" is a verb. One doesn't "love on", "like on", "want on" or any such thing, so why this prevalence of "hate on"? To me, it just smacks of a complete lack of creativity. Surely there are so many more ways to convey this point!
End of sermon.