If you are only getting one, and want it to go with a lot of different wardrobe bits, get the grey. I have a black one because it is dressy, but it only really works with black belt, sporran, etc. I will eventually add more jackets, starting with a grey.

If what you want is to look really sharp, the black with gauntlet cuffs has just enough of the PC look without the rather less comfy cut of the full PC getup. That's what I went with and it looks grand.

-Patrick