I'll second MDV's opinion here: Nailbomb!
Very dynamic, great clean sounds too, can do the "brutalz" if you wish it too!
And Opeth are just a super great band! Got to love them through my girlfriend, she was into them already and convinced me, that there is just so much more to them than growling / grunting vocals.. :)
Have seen them live for three or four times now, and they are just awesome! The drummer kicks ass big time, very difficult to play this stuff, and he just blasts through the set.. very cool!
I am ok with the grunting now too (i tend to listen to the guitar parts more during the grunting ;) ), but just love when Akerfeldt starts to sing with this beautiful voice! Complements each other greatly i think. :)