Im still not level 100 so maybe my point of view will change then. Back when cata first came out I decided to level my first shaman as a goblin. It was literally the most fun I ever had in this game. I love all three specs.
I have never really played my shaman outside of leveling and some light pvp here and there. I really like a challenge though and everyone says shamans are the worst. So as im writing this my shaman is level 97 and is enhance. I started doing skirmishes and bgs at 96 and I honestly have to say I really love the play style. I can see where shamans really need improvements but overall I dont see why everyone complains so much about them. I am doing really good damage and my healing is off the charts. I usually am top heals even with actual healers in the bgs.
Like I said I will have to wait to become geared at 100 to really try it out, but so far I really like my shaman.
I currently have a 100 hunter which got boring fast and a 100 druid that I regret leveling so early. I actually mained my druid before WOD and now I cant play them because all three specs are boring to me.