In the big picture, shamans are the most OP. Best healer in resto, ele is very viable and is in what some consider the best comp there is in LSD 2.0. Enhancement is slightly less represented but still has viable comps and has the gnarliest burst in the game. 3 r1 viable specs that have 3 different roles. I could argue hunters or locks are superior as dps specific classes, but overall it has to be shamans with how dominant resto is while still having ele and enhance being solid specs.