As many people know cabal online Gold, hunter damage along with the TnT stun was a constant target by protesters on the pvp or hunter forums. Of course we cannot forget about retribution paladins, who although have been a terrible specc through all of 60 and 70, have been very successful and obscene in arena at level 80. And, as many people can assume where Im going with all of cabal Gold, they also have a lot of magical damage, which cannot be mitigated.
Finally, we cannot exclude rogues from this list. Even though rogues do a lot of physical damage, they also have that pesky wound poison, which does about 500 non to mitigatable damage every time it is applied on the target cheap Cabal Alz. And dont kid yourself if you think that isnt a lot of a rogues damage, because it is.