As an old ass '80s thrasher and DJ who has owned or heard pretty much all obscure eighties thrash albums, I can tell you that the following are the only ones I still listen to fairly often these days:
Sacrifice: Forward to Termination (This is my favorite)
Rigor Mortis: Rigor Mortis (second favorite) and sometimes Rigor Mortis vs. the Earth
Testament: The New Order and The Legacy
Sacred Reich: Ignorance
Hallow's Eve: Tales of Terror
Flotsam and Jetsam: No Place for Disgrace and sometimes Doomsday for the Deceiver.
Nasty Savage: Nasty Savage
Bloodfeast: Face Fate and sometimes Chopping Block Blues
Possessed: Seven Churches, Beyond the Gates, and The Eyes of Horror
Then of course Megadeth and Slayer. I don't listen to Anthrax or Metallica anymore. Once in a great while I'll bust out "Feel the Fire" by Overkill.
EDIT: I forgot Forced Entry: Uncertain Future (this album RULES)