Unholy Death Knight has one of the highest AOE potential, with a nice single target damage and [Ebon Plaguebringuer] to buff the raid, this increases the damage of magical spells by 13% and disease damage.

Gems and Enchants for Unholy Death Knight Wotlk

Unholy Death Knight Enchants

Head

[Arcanum of Torment] – Knights of the Ebon Blade

Shoulders

[Greater Inscription of the Axe] – The Sons of Hodir

Cloak

[Enchant Cloak – Greater Speed] – Enchanting

Chest

[Enchant Chest – Powerful Stats] – Enchanting

Wrists

[Enchant Bracers – Greater Assault] – Enchanting

Weapon

[Rune of the Fallen Crusader] – Runeforging

Hands

[Enchant Gloves – Precision] – Enchanting

Waist

[Eternal Belt Buckle] – Blacksmithing

Legs

[Icescale Leg Armor] – Leatherworking

Feet

[Enchant Boots – Icewalker] – Enchanting

Unholy Death Knight Gems

Meta Gem

[Relentless Earthsiege Diamond] +21 Agility and 3% Increased Critical Damage

Requires 1 red, 1 blue and 1 yellow gem

Red

[Bold cardinal ruby] +20 Strength

Yellow or Red if socket bonus is valuable + STR

[Fierce Ametrine] +10 Strength +10 Haste

Stats/Blue

[Nightmare tear] +10 All Stats

Notes

Gems and enchants should be picked depending on the stats needed. Example: If under hit cap gem and enchant until hit cap, following the stat priority.