After trying many specs, I have not found any with a higher single target DPS than my standard blood build. Please note, that I am talking single target DPS...not threat...not AOE.
In a standard tank oriented build, blood is king as far as I have tested. Now I may not be correct, but if I am not, I would like someone to post an exact spec and rotation which can beat it.
Typically in blood build, I will take 3/3 spell deflection, and probably 3/3 improved icy touch. I will probably not use Will of the Necropolis or Rune Tap, as I personally don't seem to get much use out of either.
If I really want to up my DPS, I will drop both of those, and go to a 5/5 Necrosis build.
Keep in mind I will always have the 5/5/5 trinity, plus Vampiric Blood.
Survival oriented - http://www.wowhead.com/?talent#jcErVhhIcb0fosxhxZ0gb
DPS oriented - http://www.wowhead.com/?talent#jcErVh0Icb0fosx0xZ0gh0x
Rotation is IT-PS-HS-HS-DS-DC-DC or HoW- DS-HS-HS-HS-HS
My challenge is for someone to find a tanking spec and rotation that will exceed the DPS output of my builds against a single target. I will verify both and have equal gear i can use for 2H or DW builds.