Also, figured I'd share the Walling King of NU. Kill your opponent's Steel and Poison Pokemon, and this thing becomes unstoppable.
Shuckle @ Leftovers
EVs: 80 HP, 176 Defence, 252 Sp. Def
After a few Shell Smashes, your Shuckle will take almost no damage from anything. I'll run some calcs later. After that, Toxic is really his only way of dealing damage since he doesn't get Night Shade or Seismic Toss. Power Split is fun as it cuts your opponent's Attack in half, and Rest is his best recovery.