This is a very subjective question. Personally, I would go for a 28mm or 85mm. 28mm will gives a nice wide angle field of view and 85mm is a more narrow field of view.
If it were me, I would go for the 28mm or wider first. Among other features, I like the closer focus distance from the lens and I just plain love the look of a wide angle lens.
85mm is a nice semi-telephoto lens; good for portrait type interview shoots.
I think you need to decide what kind of shooting you will be doing most and get a lens that best facilitates your work.