Hmmm, without knowing what you already have I could make a list a mile long. These aren't all new bands, but they have recent stuff out in case you haven't heard of them before.
Year Long Disaster - great new up and coming band
Porcupine Tree - progressive/heavy
Queens of the Stone Age - new album is great (actually, all albums are great)
Eagles of Death Metal - not really death metal, just good rock (features Josh Homme from Queens of the Stone Age)