ummmmm no particular order:
Death
early Deicide (especially the first three albums)
Obituary
Morbid Angel
Napalm Death
Brutal Truth
The Haunted
At The Gates
early Entombed (especially the album Left Hand Path)
and some other shit I can't really remember at the moment. I've just started to get back into it again so there's lots of new bands I haven't really heard yet (I saw a Nile clip on TV I think I'll have to check out some of their stuff). My favorite death metal album at the moment is:
\m/ R.I.P Chuck \m/