Priest, squishy but nice aoe healing spells, and nice sta buff
Druid, less squishy, nice hots also nice buff with gotw
Pally, not so squishy, no hots, difficult heal targetting (9 targets to click), but nice buffs bom and bok


think if you also want to go pvp a druid would be nicest, with the hots and bear form to turn in to when taking on a group that aims for the healer, and if you go bear you can give your group a nice 5% crit increase .. think they all have nice pro's its just a bit of seeing which con would be bad in your play style