I will list the best possible gear you can get outside of raids. These will include crafted items, rep. items, PvP items, quested items, and Emblem of Heroism items, and, of course, heroics. As of 3.1.1.
Head- Spiked Titansteel Helm
Created- Blacksmithing
Socket- Chaotic Skyflare Diamond
Bold Scarlet Ruby
Neck- Furious Gladiator's Pendant of Victory
PvP
Shoulders- Furious Gladiator's Dreadplate Shoulders
PvP
Back- Furious Gladiator's Cloak of Victory
PvP
Chest- Furious Gladiator's Dreadplate Chestpiece
PvP
Wrist- Furious Gladiator's Bracers of Triumph
PvP
Hands- Heroes' Scpurgeborne Gauntlets
Emblems(60)
Socket- Bold Scarlet Ruby
Waist- Belt of the Titans
Crafted- Blacksmithing
Socket- Bold Scarlet Ruby(x2)
Legs- Staggering Legplates
Ingvar the Plunderer- Utgarde Keep(Heroic)
Socket- Bold Scarlet Ruby(x2)
Feet- Battlelord's Plate Boots
Crafted- Blacksmithing
Socket- Bold Scarlet Ruby(x2)
Ring #1- Ring of Scarlet Shadows
Crafted- Jewelcrafting
Socket- Bold Scarlet Ruby
Ring #2- Titanium Impact Band
Crafted- Jewelcrafting
Socket- Bold Scarlet Ruby
Trinket #1-Mirror of Truth
Emblems(40)
Trinket #2-Sphere of Red Dragon's Blood
Keristrasza- Nexus(Heroic)
Sigil- Sigil of the Dark Rider
Quested- Into the Realm of Shadows
Two-Hand- Furious Gladiator's Crusher
PvP
Socket- Bold Scarlet Ruby(x2)
For more info or other choices go to:
http://maxdps.com/deathknight/unholy.php