Chained Military Gorget is the best of the three, no question. It has less stamina than the crafted one, but more than makes up for it with far superior avoidance and the +Hit for threat.
But the best neck for the 10-man/heroic/crafted level is Drakescale Collar from Sapph/Maly quest reward. It has by far the highest stamina plus good avoidance.
Titanium and Autopsy are about equal, and inferior to the two above. One has a little more stamina, the other has a little more avoidance. I would maybe go with Titanium if you are still having to gem for Defense to stay uncrittable, since it has higher Defense.