Please note that there are no spoilers. I'm just listing what gear for which spec drops in which instance. I'll add the heroic drops to another thread when I get a chance. I've grouped the elemental and resto stuff together since its pretty similar, enhancement stuff is below. I also have not added any quest rewards or anything, these items are only from dungeons.
Dungeon Required Levels:
-Ahn'kahet: 73-75
-Azjol-Nerub: 73-75
-COT: Culling of Stratholme: 80
-Drak'tharon Keep: 74-76
-Gundrak: 76-78
-Halls of Stone: 77-79
-Halls of Lightning: 80
-The Nexus: 71-73
-The Oculus: 80
-The Violet Hold: 75-77
-Utgarde Keep: 70-72
-Utgarde Pinnacle: 80
Resto and Elemental
Head
[item]Hollow Geode Helm[/item] Krystallus, Halls of Stone
Neck
[item]Crystal Pendant of Warding[/item] Novos the Summoner, Drak'tharon Keep
[item]Chain of Fiery Orbs[/item] Maiden of Grief, Halls of Stone
[item]Pendant of Shadow Beams[/item] Zuramat, The Violet Hold
Shoulders
[item]Overlaid Chain Spaulders[/item] Ingvar the Plunderer, Utgarde Keep
[item]Epaulets of Market Row[/item] Trash mobs, COT: The Culling of Stratholme
Back
[item]Cloak of the Darkcaster[/item] Jedoga Shadowseeker, Ahn'kahet
[item]Cape of Seething Steam[/item] Volkhan, Halls of Lightning
[item]Shroud of Resurrection[/item] Gortok Palehoof, Utgarde Pinnacle
Chest
[item]Hauberk of Totemic Mastery[/item] Drakkari Colossus, Gundrak
[item]Runic Cage Chestpiece[/item] Drakos the Interrogator, The Oculus
Wrists
[item]Glowworm Cavern Bindings[/item] Trash mobs, Ahn'kahet
[item]Dragonflayer Seer's Bindings[/item] Trash mobs, Utgarde Pinnacle
Hands
[item]Gauntlets of Serpent Scales[/item] Anomalus, The Nexus
[item]Gauntlets of Dark Conversion[/item] Malganis, COT: Culling of Stratholme
Waist
[item]Wing Cover Girdle[/item] Anub'arak, Azjol-Nerub
Legs
[item]Infection Resistant Legguards[/item] Trollgore, Drak'tharon Keep
[item]Kilt of Molten Golems[/item] Volkhan, Halls of Lightning
Feet
[item]Treads of Altered History[/item] Chrono-lord Epoch, COT: Culling of Stratholme
[item]Boots of the Portal Guardian[/item] Cyanigosa, The Violet Hold
Rings
[item]Necklace of the Chrono-Lord[/item] Chrono-Lord Epoch, COT: Culling of Stratholme
[item]Arcane Focal Signet[/item] Moorabi, Gundrak
[item]Band of Glittering Permafrost[/item] Keristrasza, The Nexus
[item]Signet of Ranulf[/item] King Ymiron, Utgarde Pinnacle
Trinkets
[item]Soul Preserver[/item] Malganis, COT: Culling of Stratholme
[item]Tome of Arcane Phenomena[/item] Ley-Guardian Eregos, The Oculus
Weapon
[item]Beguiling Scepter[/item] Malganis, COT: Cullling of Stratholme
Shield
[item]Tharon'ja's Aegis[/item] The Prophet Tharon'ja, Drak'tharon Keep
[item]Tor's Crest[/item] King Ymiron, Utgarde Pinnacle
Enhancement
Head
[item]Helmet of Living Flesh[/item] The Prophet Tharon'ja, Drak'tharon Keep
[item]Headguard of Westrift[/item] Ley Guardian Eregos
Neck
[item]Slasher's Amulet [/item]Prince Taldaram, Ahn'kahet
Bracers
Gloves
[item]Tear-Linked Gauntlets[/item] Svala Sorrowgrave, Utgarde Pinnacle
Shoulders
[item]Spored Tendrils Spaulders [/item] Trash mobs, Ahn'kahet
[item]Spaulders of Skillful Maneuvers[/item] Mage Lord Uron, The Oculus
Back
[item]Embrace of Sorrow[/item] Maiden of Grief, Halls of Stone
[item]Centrifuge Core Cloak[/item] Varos Cloudstrider, The Oculus
Chest
[item]Linked Armor of the Sphere[/item] Tribunal Chest, Halls of Stone
Wrists
[item]Darkweb Bindings[/item] Trash mobs, Drak'tharon Keep
[item]Tornado Cuffs[/item] Ionar, Halls of Lightning
Hands
[item]Dragon Stabler's Gauntlets[/item] Prince Keleseth, Utgarde Keep
Waist
[item]Waistband of the Thuzadin[/item] Salramm the Fleshcrafter, COT: The Culling of Stratholme
[item]Xevozz's Belt[/item] Xevozz, The Violet Hold
Legs
[item]Cannibal's Legguards[/item] Slad'ran, Gundrak
[item]Leather-Braced Chain Leggings[/item] Loken, Halls of Lightning
Feet
[item]Cleated Ice Boots[/item] Anomalus, The Nexus
[item]Boots of the Terrestrial Guardian[/item] Trash mobs, Halls of Stone; Trash mobs, Halls of Lightning
Rings
[item]Jedoga's Greatring[/item] Jedoga Shadowseeker, Ahn'kahet
[item]Palladium Ring[/item] Trash mobs, Halls of Stone
[item]Bjarngrim Family Signet[/item] General Bjarngrim, Halls of Lightning
Trinkets
[item]Amulet of the Stampede[/item] Gal'darah, Gundrak
[item]Vestige of Haldor[/item] King Ymiron, Utgarde Pinnacle
Weapons
[item]Summoner's Stone Gavel[/item] Novos the Summoner, Drak'tharon Keep
[item]Arm Blade of Augelmir[/item] Dalronn / Skarvald, Utgarde Keep