Full set bonuses
A majority of armor sets give set bonuses. These bonuses are only given when you are wearing the full set.
Bonuses
Leather (Masterful Quality): Ranger Danger - Absorption and Trueshot.
Umbrium: PPE - Strength and Immunization.
Gold: Magic Infusion - Magic Shield and Magic Focus.
Gold Book Wyrm Scale: Magic Infusion - Magic Shield II and Magic Focus II.
Neptunium: Neptune's Blessing - Swift Swimming and Water Breathing.
Silver: Quicksilver - +50% Movement Speed and Cure
Steel: Dragonsteel :) - Immunity to burning and +50% fire damage resistance.
Myrmex Chitin Armor: Millipede - +1 Step Height.
Death Worm Chitin Armor: Shai-Hulud - +50% Dig Speed.
Golem Armor: The Rock - Repulsion and Diamond Skin. Note: If every piece is Masterful, then each buff applied by armor is increased to level two.
Cow Leather: Moo - Moo (Moo like a cow)
Tide Guardian Armor: Per armor piece, no official name- Gives Water Breathing, and one level of Strength per piece when wet.
Scarlite Armor: Blood Curse - Vulnerability and Rage IV
Ninja Armor: Teleports Behind U - Skystride and Forceful VIII
Wizard Armor: Wizard 101 - (1/3) 1 Mana Regen, (2/3) 1 Mana Regen, (3/3) Teleportation (Randomly teleports user up to 50 block in any direction) and 1 Mana Regen.
X407 Prototype Armor: Power Armor - (Helmet) Night Vision, (Chestplate) Strength I, (Leggings) Jump Boost IV, (Boots) Fall Resistance.