1) It has made a unique sound all its own, which is hard to do in our Limp Bizkit, Korn-fed world of music.
2) The group brings a magnifying glass to America to probe the problems in our western society.
3) Whether or not you want the politics, System of a Down will suck you in with its music and blast your senses with its energy, their live performances really speak for themselves.
4) The music has its roots in straight-out metal, but always manages to stray far from convention, just one of the things making it the most invigorating, original, fantastic band of all time.
5) They create a wild ride into the musical world of singer Serj Tankian and guitarist Daron Malakian. Once you start riding you'll never want to stop.
Thats my quick un-biased review of system of a down 
oh yeah err Korn suck, so do Pantera 