If you dig deep enough there are actually threads that have math done on the tanking enchants. Additionally this question has been asked easily x5 times in the last week in recent threads all giving the same information I'm about to give you....
The biggest thing you need to understand is that you could enchant your weapon with [Chocolate Cake] and it wont make or break you. That's why you see people talking about taking the glow
Blood Draining is the best EH (Effective Health, Stamina + Armor) enchant. Typically the best all around for progression raiding in ICC 10/25, because EH is a favored way to gear for that instance.
Mongoose is the best threat enchant and very comparable to Blood Draining.
Blade Ward is the best Avoidance enchant.
There is something so appealing about backhanding someone across the face with a shield.