This is a metal group that both of my sons (Josh and Sam) have been enjoying. They stand out from a lot of the metal that my son, Sam, is into - maybe it's the humor of their lyrics, or the fact that everyone in this Southern California based band is ethnically Armenian - and that certainly flavors their sound.
Don't get me wrong - while there's some alternative sounding moments, this is contemporary metal which is a lot harder than the metal of the 80's. (Some of the other metal bands Sam is listening to - Fear Factory, Disturbed, Stone Sour and Stratovarius.)
For more on System of a Down, here are links to iTunes, Amazon, and AllMusicGuide.