Another album you might want to checkout is Slipknot's Iowa. That has been playing in my CD player every night since I bought it about a month ago. Really good CD!
I also recomend picking up Reign in Blood. In my opinion it is the heaviest/best Slayer album ever released, and yes I have God Hates Us All.
Another cool band you should check out is Entombed. Primarily, Wolverine Blues and/or Hollowman. Those two albums are in my opinion as good as Reign...