My list.
I can only talk about what I have.
Rad/Rad - my all around player. Great AoE. Great for team missions. Pretty damn tough bulldozer.
Stone/Spine - my farmer. Complete buzzsaw. Combine spine burst with quills and mud pots… ouch! I never see his health move. I didn’t even take Granite armor. No need.
Willpower/Claws - who needs endurance!
with minimal slotting, this tank NEVER stops. I solo him a good bit.