My shaman is my favorite alt, actually, and essentially my second favorite class behind my main, a hunter. Healing isn't complex as it is for priests, but I've always enjoyed healing on him. Also, enhancement is a hell of a lot of fun, and ele has gotten better, but I haven't played the game much since last February so I'm not sure about current numbers and things. Additonally, resto shamans have been able to deal pretty good damage in 5 mans in full healing gear and ele shamans can also heal quite well on top of doing damage, though that will likely change in Cata. My shaman has always been the most fun toon to play in five mans because there has always been something to do.