Apocalyptica

I was first introduced to this band when I heard an album composed entirely of Metallica covers. I know, a string quartet covering metal bands aren't exactly new hat, but listen to the work on their 2000 album Cult. Apparently, they have vocals in addition to their bitchin' cello work (EDIT: No, they don't). Note that all the tracks are originals, except for the last three, In The Hall Of The Mountain King, Until It Sleeps and Fight Fire With Fire. The first is a great foray into quite possibly the most well-known classical song of all time (along with Vivaldi's Spring, a song that everyone instinctively knows, but would be hard pressed to name), while the next two are some more Metallica covers. AWESOME!

P.S.: If you want the rest of Vivaldi's Four Seasons, you can get it here. Good Baroquey stuff.