Cancer - Death Shall Rise is a great one to start with.
Cianide - Gods of Death is a good starter, but The Dying Truth and A Descent Into Hell are awesome as well.
Coroner - Their first 2 albums (R.I.P., Punishment for Decadence)are more thrash oriented, the next 2 (No More Color and Mental Vortex) are more prog thrash, especially the latter. Their last album, Grin, is boring as crap. So yeah, it's up to you where to start with the first 4 albums.
Demilich is sure as hell interesting, especially the vocals, but those riffs are mind blowing. Adramalech is probably the one band most similar to Demilich. I've only listened to Psychostasia once but I do remember enjoying it.
Demigod - Slumber of Sullen Eyes is fucking awesome. That's all I gotta say.
Nuclear Assault - Survive - YES! Game Over and Handle With Care are good too, but Survive is my favorite.
Entombed - Left Hand Path and Clandestine are all you need.
Pestilence - Consuming Impulse and Malleus Maleficarum (a lot more thrash oriented) are my favorites. Testimony of the Ancients and Spheres are good too, just very different.