16-50 f2-2.8 definitely. When I first using nx1, I expect the fast auto focus tracking in video is working with any samsung lens. but not the case. most lens is not really useful at all for tracking in video. only some new lens works. the 16-50 f2-2.8 is among the best one. Very similar performance to the sony a6300/6500 system. add OIS, 120p full hd. This lens is a perfect mate to nx1.