Mara's:
1) Hell Duriel
2) Hell Baal
3) Hell Mephisto

Herald of Zakarum:
1) Hell Cow King
2) Nightmare Baal
3) Nightmare Diablo (Hell Mephisto is right behind him though)

Isn't CoA a runeword :O

Oh yeah, I found a rare claw with 3x durability. That means the game calculated it as a unique but there was no unique version of that item -_-. I feel raped by the game when it does that to me.