The following is a list of armor type items that can be found in the game:

Head:
Helms
Spirit Stones (Monk only)
Voodoo Masks (Witch Doctor only)
Wizard Hats (Wizard only)

Shoulders:
Pauldrons

Torso:
Chest Armor
Cloaks (Demon Hunter only)

Wrists:
Bracers

Hands:
Gloves

Waist:
Belts
Mighty Belts (Barbarians only)

Legs:
Pants

Feet:
Boots

Jewelry:
Amulets
Rings

Off-Hand:
Shields
Mojos (Witch Doctor only)
Orbs (Wizard only)
Quivers (Demon Hunter only)

Follower Items:
Enchantress Focuses
Scoundrel Tokens
Templar Relics