Fave 80's THRASH outside the big 4 !!!!

Here are some of my favorites:

1985 Celtic Frost - To Mega Therion (Switzerland)
1985 Exodus - Bonded By Blood (USA)
1986 Watchtower - Energetic Disassembly (USA)
1987 Carnivore - Retaliation (USA)
1987 Mekong Delta - Mekong Delta (Germany)
1987 Sodom - Persecutoin Mania (Germany)
1987 Testament - The Legacy (USA)
1987 Whiplash - Ticket To Mayhem (USA)
1987 Sacred Reich - Ignorance (USA)
1988 Destruction - Release From Agony (Germany)
1988 Kreator - Terrible Certainty (Germany)
1988 Mekong Delta - The Music Of Erich Zann (Germany)
1988 Sabbat - History Of A Time To Come (UK)
1988 Wargasm - Why Play Around? (USA)
1989 Exodus - Fabulous Disaster
1989 Kreator - Extreme Aggression (Germany)
1989 Mekong Delta - The Principle Of Doubt (Germany)
1989 Nuclear Assault - Handle With Care (USA)
1989 Paradox - Heresy (Germany)
1989 Rigor Mortis - Freaks (USA)
1989 Sepultura - Beneath The Remains (Brazil)
1989 Testament - The New Order (USA)
1989 Viovod - Nothingface (Canada)

Best Thrash_Album in my opinion is Wargasms "Why Play Around". Only few people seem to know them, but they were great ;)
 
The big four can be somewhat anoying from time to time, they are definatly not the best in thrash.

Whiplash
Dark Angel
Vio-Lence
Annihilator
Overkill
Possessed (like KMADD said, their Death metal, but I think that Seven Churches is a bit thrashy)
Kreator
Sodom
DRI
Iced Earth (some of their stuff on night of the stormrider, the self-titled or burnt offereings sound pretty thrashy to me)
Testament
Flotsam and Jetsam
Tankard
Sadus

That's all I can think of right now