Taylor Swift Covers Eminem Song [VIDEO]

Just when I thought I have heard every possible mash up between artists covering each other's tunes or doing a collaboration, I stumbled upon this video of  21 year old country starlette, Taylor Swift, covering a song by rapper Eminem.   Really!?  Take a gander:

Though I'd much rather watch the video on mute, it did make me think back to some of my favorite collaborations.  Ones worth turning the volume up! BJ compiled a killer list.  What's your fave? And have you stopped googling Taylor Swift images yet?