Regirock

Regirock got the short end of the stick: its specially based counterpart, Regice, is weak to a single rare special type, whereas Regirock is weak to Earthquake, Brick Break, and Meteor Mash. This does not hamper it as much as you might believe, however, as even an uninvested Regirock can survive Adamant Choice Band Medicham's High Jump Kick. Furthermore, it has crucial resistances to Normal and Flying, while Regice does not have any special resistances save Ice. With decent coverage between a STAB Rock attack and Superpower, Regirock can counter Dragon Dance Tyranitar, Salamence, and Gyarados--though watch out for Hydro Pump. Finally, if there is an enemy Pokemon your team can't handle, Regirock always has a trump card in Explosion to blast that opposing Pokemon out of the way.