A good site for LISTENING to metal.

Pandora Internet Radio - you tell them what you like, they play stuff like it. Great site for finding new bands or chilling to music. They have loads of metal, but also other stuff.

Rather limited, though. And it doesn't recognize a lot of the bands I would enter into its engine. It doesn't even accept Borknagar.

I do credit Pandora for my original discovery of Kaamos.
 
Pandora has spotty coverage of obscure bands, I'll admit. But I've found a number of bands through it. It's really good for people getting into metal.