Nitride is far and away the toughest most durable of the finishes you listed. I have limited experience with the others. Except for improving lubricity of a bolt or auto slide which Black-T is good for I would not consider anything other than Nitride.

"When you disarm the people, you commence to offend them and show that you distrust them either through cowardice or lack of confidence, and both of these opinions generate hatred." Niccolo Machiavelli