Frost vs Unholy vs Blood

Hello Guys,

I am thinking about starting a DK, to mainly play PVP.
Whenever WotLK launched on Blizzard, I used to play Unholy. But since then, I have not played DK anywhere else, therefore I know nothing anymore about this class.
I would like to know which spec is better for PVP.

I have a friend that plays healer and thought it would be funny to play Blood, since it is super tanky on BGs.
But if you guys can give some tips regarding the specs, it would be super helpful so I can choose it. I have watched a lot of videos about it but wanted to hear from the community here who actually plays the class on this server.

Cheers.

Well all of them work in bgs.
In 1vs1 unholy/blood hybrid is the best.
In 2vs2 frost and unholy work, with frost being better imo with dk/healer.
For 3vs3 its unholy.
Blood can be fun with lots of pve armor pen pieces/shadowmourne. I recall a guy reaching 2.2k in 2s playing like this.