Personally, I've had the most success with Onix, Turtwig and Shellos. The biggest problem here is Cranidos' Headbutt, which can OHKO less durable Pokémon like Budew, Piplup, Buizel and Psyduck.
Turtwig gets STAB Absorb, and while it can't usually KO Cranidos, it can tank a Headbutt and recover enough to take a second before knocking it out.
Shellos is kind of the same deal, with powerful STAB Water Pulse and Mud Bomb/Mud Slap for clutch accuracy drops.
Onix is a fun choice because his awesome Defense stat shrugs off Headbutt and eventually, a combination of Screech and Rock Smash should bring it down fairly easily. Geodude works here too, but it doesn't get Screech.
