Fuck, this will be tough. I'll just pick a defining song from some of the defining bands. WARNING: This will probably seem rather cliche.
Suffocation - Leige of Inveracity
Nile - Unas, Slayer of the Gods
Cannibal Corpse - Hammer Smashed Face
Morbid Angel - Immortal Rites
Deicide - Lunatic of God's Creation
Sepultura - Troops of Doom
Possessed - Exorcist
ahhhh...fuck it. This is too hard for me.
Sorry...I realize this list only skims the variety of bands death metal has to offer.