Torkoal has naturally high Defense, very passable Offensive Stats, and can use Amnesia just once for a Special Defense stat as good as its Defense. One turn of setup for a very good Multipurpose Wall.
It can pack Will-O-Wisp OR Toxic for crippling, and packs power Fire-type STABs, as well as potent other attacks, like Body Slam, Gyro Ball, and Earthquake.
WALLING MOVESET:
Heat Wave (STAB)
Amnesia (Just one, and you've got very frightening bulk)
Gyro Ball (Backup attack)
Protect (use to negate an attack)
EDIT:
(Wall-Stall):
Will-O-Wisp
Sleep Talk / Amnesia
Rest
Heat Wave / Return / Gyro Ball / Earthquake