Depends really:
If the Mob is undead: Pally, 2 Necros, and a Cleric
Normal Mobs: Warrior (me usually), Necro (me, but good for patching in case), Any healer is good- Cleric is best because CHA ia a main stat, Shammy at 51+ for avatar, Druids for adding damages, and Wizzy/Monk/Rogue, Prefered Wizzy because no complaints about repairs
Pet groups: 2 Necros, 1 Mage, 1 Enc for mana