DK Tanks  

Honestly to answer your question I would go with the Blood Tree. I feel it would allow maximum tanking ability and AoE activity at the same time. I would give you a full spec but I have just recently made my DK after Dinging lvl 80 on my Orc Hunter and Nelf Priest. My 2 cents.

Haven't messed with DK that much yet but most say Frost is the best tank spec. Now from what I've seen they are not great at tanking and alot of healers refuse to heal for teams when DK tank. They say they take too much damage. Now I'm not sure which spec they were but they said they usually dps instead of tank so they probably didn't have best gear for job. I've been in the looking for team quite a few times when they ask what the tank is. I'd still give it a try myself as I think if your good at your job there should be no problem. Good luck on your task though. Go prove some of the healers that you can tank! HEHE

WHAO. The LAST thing you want to do is spec blood. Some people say unholy, whilst most say frost.

My death knight is frost, because i have a DPS class and a HEALER class, so i figured i'd try being a tank.

As long as 'retards' in my group don't aggro other mobs in the area / attack mobs that i ain't - Then my team should be fine - (As long as the healer is doing their job too...)

My boyfriend is unholy spec... my brother is blood spec. My brother is better at fighting alone but cannot hold very good aggro in a team. My boyfriend can hold most aggro, because of the AOE's... but the healer will get aggro half the time. My DK (frost spec) can hold aggro fine. I use my AOE's as often as possible to all aggro is on me... + death grip is always awesome for the strays...

Though to be perfectly honest... most of the spec's can tank OKAY-ish if you use frost presence.

Anyhoo-

Good luck with your death knight and tanking ;)

Here's how I view them..

Blood Tank - has decent aggro coz of the attack power and can definitely take care of him/herself since he can heal. He has talents that can heal him quite decently.

Frost Tank - has above decent aggro since his/her frost spells deal adequate damage. Plus, his/her talents tend to slow the target down and gives ample defense on him/her.

Unholy Tank - has the best aggro when it comes to AoE tanking coz of his/her AoE spells. Bone armor is leet and is the best of the 3 35-point talent from their respective trees.

Hope that helps.

frost is the best for tanking, espiecially with the 10% increase in hp, put a little bit in blood too