OK. That was... awesome. Sure - there's harder metal out there, but as much as, say, Amon Amarth has awesome music, death metal vocals aren't my thing. The symphonic end with Nightwish and Within Temptation, a little Five Finger Death Punch, a little Drowning Pool...
And these guys rock. And they're willing to go out on a limb, and to look silly doing so. Take a look at the vid for Gangnam Style.
Or Shakira's Waka Waka - I haven't listened past her first couple albums but the lady does have talent (not just looks), and these guys put an entirely new spin on it.
You can also find covers of Gangsters Paradise, Eye of the Tiger, The Final Countdown, and music from Frozen, among other things. Ant they're on iTunes, Amazon, etc.