I remember that the coolest thing about the very beginning of the thrash movement was the Metal Massacre and Best of Metal Blade records. I owned all three of the Best of Metal Blade double albums at one time or another. I got turned on to *SO* many new bands that way.
Fates Warning
Trouble
Hallow's Eve
Bitch
Celtic Frost
Voivod
Lizzy Borden
Omen
Destruction
Sentinel Beast
Hirax
Flotsam and Jetsam
Sacred Reich
Candlemass
and many, many other cool bands whose albums I never did pick up...but some of them had really great songs. All from the Best of Metal Blade series.
Other honorable mentions go to Obsession, Tygers of Pan Tang....there are others I'm sure I've forgotten. Even though I always HATED HATED HATED Grim Reaper with a passion, Steve Grimmett's follow up band Onslaught wasn't too bad. Under-rated IMO.
I'm sure there's stuff I'm forgetting. It comes with getting old.