Ret pally all the way. Divine storm with normal dw tentacle weapon one shots everything up to late tbc. In wotlk, I pull non-stop (10-15) mobs at all times. Slowing down only for quest items etc. no need for defensive CDs with healing from divine storm.
With RAF you need one run per instance and you're done. Don't forget the arena quests in tbc and wotlk (ring of blood etc), with RAF they are worth a level at least if you do them as soon as they are available.