Named item sets

Item sets give bonuses when you are wearing 2 or more items in the set.

Korthos Island Item Sets
The first item in the set is an End Quest Reward Item from the Sacrifices Quest, the second item in the set is an End Quest Reward item from the The Salvation of Korthos (Misery's Peak) Quest.

Anger's Set

 * Anger's Step - Boots: Expeditious Retreat (CL:1, 2/rest), Jump +3
 * Anger's Gift - Necklace: Strength +1, Resistance +1
 * Set Bonus - To-Hit Bonus +2 (untyped?, stacks with competence)

Arcane Set

 * Arcane Goggles - Goggles: Concentration +3, Power I
 * Arcane Necklace - Necklace: Intelligence +1, Charisma +1
 * Set Bonus - 15% improvement to 1st level spells

Archivist's Set

 * Archivist's Goggles - Goggles: Concentration +3, Power I
 * Archivist's Necklace - Necklace: Minor Mnemonic Enhancer (doesn't cure Feeblemind)
 * Set Bonus - Spell Points +20

Devoted Set

 * Devoted Goggles - Goggles: Heal +3, Power I
 * Devoted Necklace - Necklace: Wisdom +1, Resistance +1
 * Set Bonus - +20% Healing to 1st level spells

Nimble Set

 * Nimble Grasp - Gloves: Tumble +3, Striding 5%
 * Nimble Brooch - Necklace: Dexterity +1, Resistance +1
 * Set Bonus - To-Hit Bonus +1, +2 Damage to Sneak Attacks

Pathfinder's Set

 * Pathfinder's Boots - Boots: Tumble +3, Striding 5%
 * Pathfinder's Necklace - Necklace: Dexterity +1, Resistance +1
 * Set Bonus - To-Hit Bonus +2

Protector's Set

 * Protector's Gloves - Gloves: Intimidate +3, DR 1/-
 * Protector's Brooch - Necklace: Strength +1, Resistance +1
 * Set Bonus - Light Fortification, Insight AC Bonus +1

Troubleshooter's Set

 * Troubleshooter's Goggles - Goggles: Spot +3, Listen +3
 * Troubleshooter's Necklace - Necklace: Dexterity +1, Resistance +1
 * Set Bonus - AC +1, Open Lock +3, Disable Device +3

Prestige Enhancements Item Sets
These item sets appeared as from Module 9, you must be at least 18th level in one class to have the Prestige Enhancement requirements. Some items may not have requirements but are still based on being a Prestige Class. They may be found as Quest Rewards in the Devil Battlefield.

Thanks to Cleanup of Ghallanda for compiling the list of items and making them available on the DDO Forums at http://forums.ddo.com/showthread.php?t=185777

Air Savant

 * Calitomes' Sash - (Belt) Superior Spark VIII (CL:1, 3/3), Wizardry VI
 * Calitomes' Ring - (Ring) Charisma +6, Exceptional Dexterity +1
 * Set Bonus: Electricity Spells +5% to Critical Hit, Electricity Spell Damage increased by 0.50

Arcane Archer

 * Gilvaenor's Necklace - (Necklace) Constitution +6, Attack Bonus +2

Archmage

 * Rahkir's Sash - (Belt) Archmagi (+200 SP Wizard, +400 SP Sorcerer), Superior Efficacy VIII (CL:1, 3/3)
 * Set Bonus: Gain +5% chance spell Critical Hit, Spell critical damage increase 0.50

Assassin

 * Awanahu Sash - (Belt) Constitution +6, Proof Against Poison
 * Whisper Ring - (Ring) Dexterity +6, Exceptional Intelligence +1
 * Set Bonus: Bonus To-Hit and Damage to Sneak Attacks, 20% less threat, If have Assassin III Enhancement chance with weapons to apply a Level Drain effect.

Deepwood Sniper

 * Conner's Pendant - (Necklace) Constitution +6, Hide +15
 * Set Bonus: 5% Ranged Alacrity, +2 To-Hit

Defenders of Siberys

 * Belt of the Defenders of Siberys - (Belt) Constitution +6, Greater False Life

Dragonmark Heir

 * Dragonmarked Necklace - (Necklace) Constitution +6, Minor Lesser Dragonmark Enhancement
 * Set Bonus: 2 additional uses of Greater Dragonmark per rest

Earth Savant

 * Thamor's Belt - (Belt) Superior Erosion VIII (CL:1, 3/3), Wizardry VI
 * Set Bonus: Acid Spells gain +5% to critical hit, Acid Spell critical damage increased by 0.50

Fire Savant

 * Singed Belt - (Belt) Wizardry VI, Superior Inferno VIII (CL:1, 3/3)

Frenzied Berserker

 * Knost's Belt - (Belt) Constitution +6, Greater False Life

Henshin Mystic

 * Oremi's Necklace - (Necklace) Constitution +6, Ki On Hit +1
 * Oremi's Ring - (Ring) Wisdom +6, Exceptional Constitution +1
 * Set Bonus: 1d6 Fire Damage per Attack

Hunter of the Dead

 * Ann Velsing's Belt - (Belt) Constitution +6, Undead Guard
 * Set Bonus: 3 extra uses of Remove Disease per rest, If have Hunter of the Dead 3 Enhancement additional damage versus Undead

Kensai

 * Verik's Necklace - (Necklace) Constitution +6, Lesser Action Boost Enhancement
 * Verik's Ring - (Ring) Strength +6, Exceptional Constitution +1
 * Set Bonus: +2 Exceptional Melee To-Hit, +3 Confirm Criticals, If have Kensai III Enhancement +3 Exceptional Bonus To-Hit

Knight of the Chalice

 * Lorinthor's Belt - (Belt) Constitution +6, Heightened Awareness I
 * Lorinthor's Ring - (Ring) Strength +6, Exceptional Charisma +1
 * Set Bonus: Spell Resistance (22), If have Knight of the Chalice III Enhancement additional damage with weapons versus Evil Outsiders

Mechanic

 * Mechanics's Belt - (Belt) Constitution +6, Proof Against Poison, Fire Resistance (10)
 * Set Bonus: Open Locks +15, Disarm Traps +15, +2 Exceptional Bonus to all Dexterity based Skills

Ninja Spy

 * Nyoko's Necklace - (Necklace) Invisibility (CL:15, 3/3), Constitution +6
 * Nyoko's Band - (Ring) Wisdom +6, Exceptional Dexterity +1

Occult Slayer

 * Vorne's Belt - (Belt) Constitution +6, Greater False Life
 * Set Bonus: +2 Exceptional Bonus to Willpower saves, +2 Exceptional Bonus to Reflex saves, Spell Resistance (22)

Pale Master

 * Eerie Belt - (Belt) Superior Efficacy VIII (CL;1, 2/2), Archmagi

Purple Dragon Knight

 * Draconic Necklace - (Necklace) Greater Heroism (CL:11, 1/1), Constitution +6
 * Set Bonus: 10% additional threat, +1 Exceptional Bonus To-Hit

Radiant Servant

 * Amara's Belt - (Belt) Superior Ardor VIII (3/3), Wizardry VI
 * Set Bonus: Additional Turn Undead attempt, Exceptional Bonus to Turn Undead

Ravager

 * Colethenis's Belt - (Belt) Constitution +6, Seeker +2
 * Set Bonus: % chance to inflict damage over time effect

Shintao Monk

 * Shintao Cord - (Necklace) Constitution +6, Concentration +15
 * Shintao Ring - (Ring) Wisdom +6, Exceptional Dexterity +1
 * Set Bonus: +2 Exceptional Bonus to To-Hit and Damage

Spellsinger

 * Shiona's Pendant - (Necklace) Superior Potency VI, Wizardry VI
 * Set Bonus: 2 additional Bard songs per rest

Stalwart Defender

 * Stalwart Necklace - (Necklace) Constitution +6, Lesser Action Boost Enhancement
 * Set Bonus: 15% additional threat from melee attacks, If have Stalwart Defender III Enhancement +2 AC Bonus (Stacks)

Tempest

 * Kilau's Necklace - (Necklace) Constitution +6, Balance +15
 * Kilau's Band - (Ring) Dexterity +6, Exceptional Wisdom +1
 * Set Bonus: 1d4 Additional Slash Damage, If have Tempest III Enhancement +3 To-Hit Bonus

Thief Acrobat

 * Morah's Belt - (Belt) Jump (CL:15, 3/3 Charges), Constitution +6, Tumble +15
 * Morah's Band - (Ring) Dexterity +6, Exceptional Dexterity +1
 * Set Bonus: +15 to Jump, % chance weapons will unbalance an opponent

Virtuoso

 * Smedgar's Necklace - (Necklace) Superior Potency VI, Wizardry VI
 * Smedgar's Ring - (Ring) Charisma +6, Exceptional Dexterity +1
 * Set Bonus: Additional Bard Song per rest, Extend Spell 2 Spell Points less

Warchanter

 * Torin's Choker - (Necklace) Superior Potency VI, Wizardry VI
 * Set Bonus: Additional Bard Songs after resting, Maximize Spell costs 4 Spell Points less, Extend Spell costs 1 Spell Point less

Warpriest

 * Morgana's Belt - (Belt) Constitution +6, Attack Bonus +2
 * Morgana's Ring - (Ring) Wisdom +6, Exceptional Strength +1
 * Set Bonus: 2 additional Turn Undead per rest, +2 Exceptional Melee Bonus To-Hit

Water Savant

 * Telvi's Sash - (Belt) Superior Freeze VIII (CL:1, 3/3), Wizardry VI
 * Set Bonus: Cold Spells gain +5% chance to Critical Hit, Cold Spell Critical Damage increased by 0.50

Wild Mage

 * Kormor's Belt - (Belt) Wild Mage Surge (CL:15, 3/3), Archmagi, Confounding Enchantment
 * Set Bonus: All Level 8 and lower spells gain +2 to die roll to penetrate target's Spell Resistance.

Glacial Assault Set

 * Bracers of the Glacier - Bracers: Archmagi,, Fire Shield (cold version, 10% chance when attacked)
 * Gloves of the Glacier - Gloves: ,
 * Dragontouched Armor - Glacial Assault Sovereign Tier Property
 * 2 Item Set Bonus -
 * 3 Item Set Bonus -

Levik's Defender Set

 * Levik's Bracers - Bracers: Levik's Defender, Healing Amplification 20%,
 * Levik's Defender - +5 Mithral Tower shield (Blocking DR 15 (base 8)): Levik's Defender,, Healer's Bounty (2% chance of casting Heal spell when damaged)
 * Dragontouched Armor - Levik's Defender Sovereign Tier Property
 * 2 Item Set Bonus - +3 Insight Bonus to AC, 20% Additional Melee Threat, Unlisted Fortitude and Will Save +1 (Stacks)
 * 3 Item Set Bonus - +5 insight AC, 30% Additional Melee Threat
 * Hound of Xoriat Loot (Xy'zzy Warded Chest)

Lorrik's Champion Set

 * Lorikk's Champion - +5 Mithral Large Shield (Blocking DR 15 (base 8)): Lorrik's Champion, Eternal Faith,
 * Mithral property on this shield is currently broken, players still suffer -15% Arcane spell failure and -1 Armor check penalty
 * Lorrik's Necklace - Necklace: Lorrik's Champion,, ,
 * Dragontouched Armor - Lorikk's Champion Sovereign Tier Property
 * 2 Item Set Bonus -
 * 3 Item Set Bonus -
 * Hound of Xoriat Loot (Xy'zzy Warded Chest)

Tharne's Wrath Set

 * Tharne's Bracers - Bracers:, Armor Bonus +6
 * Tharne's Goggles - Goggles: Backstabbing +5, True Seeing, ,
 * Dragontouched Armor - Tharne's Wrath Sovereign Tier Property
 * 2 Item Set Bonus - Ghost Touch and -20% Melee Threat
 * 3 Item Set Bonus - Feather Falling