I think #4 and #6 seem to be the best necklines for you. (I am commenting the necklines only, not the colours or the details of the garments.)
Tips: Among the factors to consider when choosing a flattering neckline are: (1) your face shape and size, (2) your neck length, and (3) whether the lines of your chin are curvy or angular. With a relatively large face, and/or with a short neck, necklines that are a little deeper may look better than turtlenecks and crew necks. And mirroring your chin lines (curvy = round necklines, and angular = V-neck) will often look harmonious.
We are all different, so what works for one person, may not work for another. For me, turtlenecks, slash necks, boat necks, as well as crew necks, scoop necks and in fact and all round necks that are not too deep, work well. I do not wear V-necks unless the line is very soft or unless they are a used as outer layers. (V-neck cardigans, for example, look ok on me if the inner layers have round lines. I aim to always wear flattering lines near my face.)
Good luck with identifying which neck lines are the best for you!