666 is

1) a German band created by Thomas Detert and Mike Griesheimer. They produce hard house and often include lyrics in Spanish (Amokk, Alarma, Bomba!) but sometimes in English (Supa-Dupa-Fly) and rarely in German. 666 is portrayed as a gothic horror style band, but is most likely just a marketing facade than an actual lifestyle. They have produced many notable Singles and Best of CDs.

2) a Norwegian first wave black metal band from North Norwegian capital Tromsø. Formed in 1982, split up in 1983. The name of the band is also spelled SæksSæksSæks (pronounced sax-sax-sax), North Norwegian for SixSixSix.

3) a czech black metal band which formed in 1983 and only released one demo: ``Nekrofilie``, the 1st ever demo on the Czech metal scene.

4) a Hungarian black metal band, a side-project of another hungarian black metal band Dusk, released the first full-length album in 2007.

5) A japanese 80's hardcore band.