Choice depends on your personal style and target market. Not that I am a pro photographer, but were I to be looking for one I'd be looking for one who was stylish and artistic, without too much of their own ego, prepared to listen. Some of the more bold signatures shout "ego" a bit too loudly for me (eg 2, 5, 8), some are too artificial and don't flow visually (4, 6). My personal favourite is 7, minus the bar on the L. That looks like a real signature, as if you are investing yourself in the business, self effacing yet stylish.