Don't even bother with a Druid, they are so subpar now. Holy Paladin, Resto Shaman, and Disc (and Holy believe it or not) Priests are all extremely viable and all have their own strengths and weaknesses. I don't really think there is a "better" choice, but at least in my opinion Priests are the way to go right now. Power Word: Shield is sooo good and although you might have a little bit harder time with Rogues you'll get scream + mind control which are exceptional if you're going to be sitting on D or if you ever have some room to CC on O.