All hybrid classes (Druid,Paladin,Shaman) best specs were pretty much the healing specs, and along with priest were all pretty good, priests being great pve healers, and paladins great pvp healers with good single target healing and plate armor. Warrior was the best tank by a decent margin with bear druid behind, and paladin tanking was not great, especially without a taunt.
Rogue and Warrior(Warrior more pve than pvp unless geared well) were great melee damage dealers, mage is great and Warlock gets stronger the further the game goes on (with having end game raid gear is very strong), although with warlock in pvp, horde is a potentially better choice as horde racials have strong stun resistance, which is a core part of warlocks with fearing especially.
Thanks!