There are a couple studio versions of this particular song, and several live versions. This live version is, without a doubt, my favorite. The raw emotion she displays while singing and playing this song is simply awe-inspiring. One other bit that really makes me enjoy it even more is when she describes the song in this way:
I sort of wrote it from the point of view of someone who is so obsessed with somebody else that they might do something violent.
Her smile at that moment, and the reaction of the host, are priceless.
What? You thought it was about something else? Oh. Sorry to rain on your parade then.