Agree with Sean; #1 just looks 'off'; rather like you caught her just as she was getting ready to pose. #2 is very nice, but two points: You've cropped her left arm along its axis which is an unforgivable sin and one light seems a bit out of place since her right shoulder is brighter than I thik is ideal.
#3 us a great concept, but for me, the DoF is just too thin. Again, there's a lot of (IMO) unnecessary light on her chest.
#4 is the winner; lovely look and very nice lighting. This one just works!