Two. It is very simple, and it wouldn't stand out too much if you were walking the streets of Nar Shadda/Coruscant with them on. The black and grey make it very good at blending in with shadows, and I like the way it looks a lot.
One would attract far too much attention if you were trying to move through a crowd. While one looks the coolest as far as black hooded armor goes; it isn't practical for crowded areas.
Three would be hard to be stealthy in unless you were using the Force or some piece of technology to blend as the red and black mark a stark, and easily seen, contrast. I like the design though.