Well then to answer your question.
From best to last.
1. Paladin. 2. Warrior. 3. Dark night
Why? Paladin offers self heal, party wide mitigation, reasonable damage, ranged cleves and good mitigation.

I think that is how most of the tank community feels. I personally play WAR, PLD. DRK not so much. It just doesn't do the job for me after Stormblood. Its all my thoughts tho.