2,3 and 5 have such great drama to them. I'm so in love with 5 though, if you just messed around with the light/dark values of the clothes more and reduced the armor on the legs(distracts heavily and unbalanced her top half) I think it'd really stand out.
Really Really like 5 mask and full armor: the whole look of "war master" is greeeat. Anyway 3 catches my eye , I think because her hair and the values of the "belt", and the fact that has more balance in terms of "skin / armor". Great job!