Hello,
These are all the WotLK reputation rewards you might be interested, if you're a Death Knight.
Also, I don't say you should get all of these rewards, they're just 'good to take'. For more information about your class, you can always go to the official forums, the wowhead forum (my personal fav.) or, of course, the WoW-pro forums
Horde Expedition / Alliance Vanguard:
Exalted:
Arcanum of the Savage Gladiator (Horde version is the same).
Argent Crusade:
Honored:
Cloak of Holy Extermination
Revered:
Fang-Deflecting Faceguard
Argent Skeleton Crusher
Frenzyheart Tribe
Exalted:
Frenzyheart Insignia of Fury
Knights of the Ebon Blade
Revered:
Arcanum of Torment
Runeblade of Demonstrable Power
Reaper of Dark Souls
Exalted:
Death-Inured Sabatons
The Kalu'ak
Revered:
Whale-Stick Harpoon
The Oracles
Revered:
Gold Star Spaulders
Exalted:
Oracle Talisman of Ablution
The Wyrmrest Accord
Exalted:
Legplates of Bloody Reprisal
Sons of Hodir
Honored:
Lesser Inscription of the Axe
Lesser Inscription of the Pinnacle
Revered:
Spaulders of the Giant Lords
Stalactite Choppser
Exalted:
Greater Inscription of the Axe
Greater Inscription of the Pinnacle
Well, I hope this little guide is useful, goodluck gathering the items you need!
~Trollvink.