Updated for WotLK Release.

Helmet

Arcanum of Torment (+50 Attack power / 20 Critical Strike Rating)

Glyph of Ferocity (34 AP, 16 hit rating) - Only if +hit is desperately needed.

Arcanum of Triumph (+50 Attack Power, 20 resilience) - A good enchant if you need help with Resilience

Shoulders

Greater Inscription of the Axe (+40 Attack Power / +15 Critical Strike Rating)

Lesser Inscription of the Axe (+30 Attack power / +10 critical Strike Rating)

Greater Inscription of Vengeance (Aldor - Exalted, +30 Attack Power/ +10 Critical Strike Rating)

Greater Inscription of the Blade (Scryers - Exalted, +15 Critical Strike Rating/ +20 Attack Power)

Inscription of Triumph (+40 Attack Power / 20 Resilience) - For your Resilience needs.

(note : Same with Fur Lining!)

Back

Enchant Cloak - Major Agility (+22 agility)

Chest

Enchant Chest - Powerful Stats (+10 all stats)

Enchant Chest - Major Resilience (+15 Resilience) - For PvP if Resilience is needed. +20 Resilience enchant is not in the game as of yet.

Bracer

Enchant Bracer - Greater Assault (+50 Attack Power)

(note: Fur Lining from Leatherworking is obviously superior)

Gloves

Enchant Gloves - Crusher (+44 Attack Power)

Enchant Gloves - Precision (+20 Hit Rating) - If you need +hit.

Legs

Icescale Leg Armor (+75 Attack Power / +22 Critical Strike Rating)

Boots

Enchant Boots - Icewalker (+12 Critical Strike Rating / +12 Hit Rating)

Enchant Boots - Greater Assault (+32 Attack Power) - If you don’t need the +hit that Icewalker offers

Ring (where applicable)

Enchant Ring - Assault (+32 Attack Power)

Weapon

Enchant Weapon - Berserking (Chance for +400 Attack Power proc / -25% of total armor) - For PvE

Enchant Weapon - Massacre (+110 Attack Power) - For PvP (-25% armor from Berserking will get you killed fast)