Apocalyptica is incredible music! I highly recommend them :)
^ that link has some samples to listen to from my favorite CD. They have evolved a bit since that CD but it's still great music.
^ that link is a listing of all of their stuff, most (if not all) of the titles have samples for listening. :)
Admittedly I have eclectic music tastes but how can you go wrong with 4 classically trained cellists playing Metallica? hehe
Their videos are pretty cool too if you ever run across them. 2 of my personal favorite videos are Harmageddon & Nothing Else Matters.
