Named chest loot

These specific items are found in chests in certain missions (generally, the same chest each time). Unlike unique quest rewards, they are not bound to the player who recieved it. Some of these items will only appear if a certain named monster is randomly spawned.

Particularly important items in the following lists include Muckbane, the Chill Shard, the Fragment of Silver Flame, the Silver Bow, the Planar Gird, and Chaosgarde, all of which provide capabilities that are impossible to find elsewhere. Other notable items are the Giant Stalker Knife, Bloodplate, and the Lightning Rod, which have powerful abilities rarely found on random items.

Sewer Rescue Loot

 * Trogskull Helmet - Helm: Resistance + 1

Smuggler's Warehouse Loot

 * Chitin Shield - +1 Light steel shield

Man Named Baudry Cartamon Loot

 * Sword of Pain - +1 Longsword: Acid touch
 * Boots of the Long Step - Boots: +5% Striding

Kobold's New Ringleader Loot

 * Bloodknuckle's Loincloth Waistband - Belt: Light Fortification
 * Bloodknuckle's Smasher - +1 Maul
 * Brakhash's Axe - +1 Battleaxe
 * Grundok's Boots - Boots: +1 Jump
 * Madoorah's Vest -- +1 Leather Armor
 * Bronkarz's Cloak -- Cloak: +1 Will save

Garrison's missing pack loot

 * Furor's hide - Cloak: Lesser Axeblock

Durk's Got a Secret Loot

 * Muckbane - +1 Club: Lesser Ooze Bane, Glass
 * Zizoo's Spangle - Trinket: +1 Intelligence
 * Rahkat's Trifle -- Trinket: +1 Charisma

Stealthy Repossession Loot

 * Gilk's Bangle - Trinket: +2 Will save
 * Jeeka's Spangle - Trinket: +2 Armor bonus
 * Wazul's Amulet - Necklace: +2 Reflex save

The Swiped Signet Loot

 * Ruined Signet Brooch - Trinket: Heal +1

Dryden Family Crypt (Catacombs 4) Loot

 * Gerard Dryden's Mace - +1 Heavy mace: Lesser Undead Bane

Irestone Inlet Loot

 * Skartongue's Ladel - +1 Light mace: Shocking touch
 * Mutiny's Tooth - +1 Dagger: Acid touch
 * Murlynd's Spoon - Trinket: creates free food in taverns

Extermination (Grey Moon Waning 4) Loot

 * Sickle of Sypheros - +1 Sickle: Frost

Redwillow's Ruins Loot

 * Drow Hunter Armor - +4 Studded leather
 * Tkorcha Family Scimitar - +3 Keen Scimitar
 * Ring of Trollish Regeneration - Ring: Minor Regeneration, Protection +2
 * (This item has been removed from game and no longer drops, per this post by Graal (DDO Developer))
 * Cloak of Troll's Resistance - Cloak: Lesser Cold Resistance, Lesser Sonic Resistance, Lesser Lightning Resistance
 * Poison-Tipped Crossbow - +3 Light crossbow: Poison
 * Scorpion Tail - +2 Shortbow: Poison
 * GranitePlate - Unknown

Gwylan's Stand Loot

 * Gwylan's Blade - +2 Shortsword: Perform +2, Roaring
 * Giant Stalker's Knife - +1 Kukri: Greater Giant bane (currently bugged, unlike other Greater Bane effects, this only gives an extra +3d6 damage, and not a +4 enhancement bonus - There will be a non-retroactive fix in a future update)
 * Minotaur hair belt - Belt: +5 Balance
 * Phiarlan Ring - Ring: +5 Perform
 * Roguebane Breastplate - +1 Breastplate: Light Fortification
 * Thuranni Stalker's Mail - +2 Chainmail
 * Barbarian's Spirit - Bracers: Rage 1/rest

Stormcleave Outpost Loot

 * Lesser Boots of Striding and Springing - Boots: +10% Striding, +5 Jump
 * Onyxhorn - +2 Dagger: Finesse
 * Robe of Winter - Robe: Improved Fire Resistance
 * Helm of Flame - Helm: Power II, Improved Devotion II
 * Giant's Roar - +2 Longbow: Roaring
 * Essence of the Scout - +2 Docent: Silent moves
 * Nuushmaar's Adamantine Tooth - +2 Rapier: Adamantine
 * Iron Cleaver - +1 Battleaxe: Acid burst

The Pit Loot

 * Muckdoom - +2 Club: Glass Ooze bane

Caverns of Korromar Loot

 * Scarf of Warmth - Necklace: Lesser cold resistance
 * Chill Shard - +2 Throwing dagger: Frost, Returning
 * Xoriat Forged Blade - +1 Longsword: Flaming, Anarchic
 * Aberrant Robe - Robe of Spell resistance 17, Wizardry II
 * Wight Hide - +2 Leather Armor: Silent moves, Shadow
 * Grudgebearer's Plate - +2 Full plate: Command

The Church and The Cult (Vampire Chest) Loot

 * Bloodplate - +2 Full plate: Deathblock
 * Silver Longbow - +2 Longbow: Holy, 1d10/19-20x3
 * Cloak of Shadows - Cloak: +7 Hide, +7 Move silently, +2 Protection
 * Shard of the Silver Flame - Trinket: Continuous Protection from evil

The Xorian Cipher Loot

 * Reaver's Ring - Ring: Light Fortification, Immunity to fear, -2 Will save
 * Planar Gird - Belt: Greater Heroism 1x/rest, Continuous Protection from chaos
 * Sign of Xoriat - Necklace: Shout 3x/rest, Spot +7, -2 Will save, Required Trait: Chaotic or UMD 20
 * Chaosgarde - Bracers: Continuous Protection from chaos, +2 Dodge bonus, Required Trait: Lawful or UMD 20
 * Chaos Band - Ring: Intelligence +3, Power III, -2 Will save
 * Tharak Fang - Trinket: Immunity to poison, +2 Constitution, -2 Will save

Haywire Foundry Loot (Vault of Night 4)

 * Bloodrage Symbiont - Trinket: Rage 3x/rest, Immunity to poison, Immunity to disease, Damage reduction 5/-, Constitution -2, -2 Will save.
 * Lightning Rod (Guaranteed at end of VoN 4) - +1 Quarterstaff: Shocking, Greater Magnetism III, Lesser Lightning Resistance

Tempest's Spine Loot

 * Maelstrom - +1 Greataxe: Anarchic, Frost
 * Choker of the Silver Tongue - Necklace: +5 Diplomacy, +5 Bluff
 * Star of Irian - +2 Morningstar: Righteous, Holy
 * Goggles of Perception - Goggles: +5 Spot, +5 Search
 * Platemail of Giants - +2 Full plate: Damage reduction 5/-
 * Shining Adamantine Plate - +2 Full plate: Immunity to poison, Command
 * Robe of Arcane Power - Robe: Potency IV
 * Eternal Wand of Charm Monster - Wand: Charm monster 2/rest, UMD DC: 6
 * Mithral Breastplate of the Elements - +1 Breastplate: Mithril, Cold resistance, Fire resistance

Invaders Rewards
The special Invaders item will show up randomly in the final boss's chest, and is determined by what kind of monster the boss is. (Note that the combination of Cold Iron and Pure Good/Holy is the only way to defeat the Damage Reduction of a Flesh Render, Fire Reaver, or Ice Flenser on Elite difficulty). Additionally, 2-5 Outsider Tokens will be in that chest, which can eventually be traded to a collector for items (in quantities of 25, apparently).
 * Beholder Optic Nerve - Necklace: Spot +7, Search +7, Beholder Ray Absorption 8x/rest
 * Garzuul's Bane - +3 Greataxe: Holy Cold Iron
 * - +4 Bastard Sword: Pure Good Cold Iron
 * Tharkuul's Bane - +3 Sickle: Holy Cold Iron
 * Tyrzza's Bane - +4 Rapier: Pure Good Cold Iron

Unique Items with Unknown or Non-Unique Locations

 * Boots of Speed- Boots, Haste 2/rest
 * Bottle of Air - Trinket: Underwater action
 * Chiku's Bauble - Trinket: Heal +3
 * Dark Blue Ioun Stone - Trinket: Listen +3, Spot +3
 * Dusty Rose Ioun Stone - Trinket: +1 Protection
 * Dwarven Thrower - +2 Throwing axe: Returning, +2d6 dmg vs Giants, +1d6 dmg vs Non-Giants
 * Enchanted Darkleaf Banded Mail - +1 Banded mail, Darkleaf, Resistance +4
 * Flamedagger - +1 Dagger: Flaming, Burning hands 3/rest
 * Flametongue - +1 Longsword: Flaming burst, Scorching ray 1/rest
 * Frostbrand - +3 Greatsword: Frost, Fire resistance
 * Keoghtom's Ointment - Trinket: Keoghtom's Ointment (5 charges)
 * Luck Blade - +2 Short sword: Resistance +1
 * Mace of Smiting - +3 Heavy mace: Adamantine, Smiting
 * Mace of the Wraith - +2 Heavy mace: Ghost touch
 * Maul of Might - +1 Maul: Force
 * Mithral Fullplate of Speed - +1 Full plate: Mithril, Haste 2/rest
 * Murlynd's Spoon - Trinket: Murlynd's Spoon 1/rest
 * Pale Green Ioun Stone - Trinket: +2 Strength
 * Pearl of the Sirines - Trinket: Underwater action, Swim +10
 * Periapt of Health - Trinket: Immunity to disease
 * Peridot Ring - Ring: +2 Will save
 * Pink Ioun Stone - Trinket: +2 Constitution
 * Pink and Blue Ioun Stone - Trinket: +2 Charisma
 * Robe of the Magi - Robe: Magi
 * Scarab of Spell Absorption - Trinket: Absorbs up to 50 spell levels
 * Scarlet and Blue Ioun Stone - Trinket: +2 Intelligence
 * Stone of Good Luck - Trinket: Good luck
 * Sunblade - +2 Short sword (1d10 slashing dmg): Flametouched iron, Evil bane, extra 1d10 + 2 dmg vs. Undead
 * Swift Demise - +1 Heavy crossbow: Crippling
 * Twig of the Giant Mage - +1 Quarterstaff: Spell Resistance 15