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

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.