Shammies have the best synergy together because you can use almost every totem if you wanted to. Not to mention people other than warriors with that spinny-whirly-thing-of-death can't get near you with staggered thunderstorm. Five groundings = dead casters before they can even damage you. And, like others have said, you can self rez and rez others. ...and I might be a little biased here, but troll females are teh sexy