While I understand the word "best" may make the question a little subjective, but from a pure PVP perspective what would be the best use of these commendations after you get to rank 60/buy all your gear?
I consider the mounts flavour items that don't do anything PVP wise (I do plan on getting them eventually though).
At the moment I have been spending 70 WZ commendations and buying the Black Market Preimum PVP Bag They contain anywhere between 2-4 of each adrenal and a Bind on Equip level 45 green item that can be sold either on the GTN or just to a vendor for credits. The risk on the box is that you may or may not get the same number of adrenals as if you had just bought them 10 for 1.
What I am wondering is/are there better things to spend the WZ commendations on that will further PVP objectives?