Although people have given their opinions, I thought I'd throw my two cents in on druids. Overall, from my experience, at 70 Balance druids can be rather scary depending upon the way in which they gear themselves. With a lot of crit, their burst can destroy rather quickly. If you're looking toward a healer class, restoration druids, in my opinion, are rather useful particularly when you can maintain hots upon your target, whilst having a three stack of lifebloom on yourself. Feral kitties can be a threat, but I'm more intimidated by a well-geared and well-played rogue.