I have to agree with the BW&BK. I end up buying at least a couple of full CDs from bands that feature on the cover CD. It's a true FAN-zine. The knowledge of the writers and the sheer enthusiasm for Metal just jumps out at you.
Other than that, I pretty much blindly buy if a band sound interesting enough. I spend $150 a week on CDs, so I have to say I end up with an awful lot of crap. Still, the diamonds shining through the rust make it worthwhile.
I've bought a few CDs based on recommendations on this forum, so that's cool.
Lee