Prefer for what? If the idea is that the name should be read, 1 and 3 are (to me) the most easily read. If it's simply a pretty picture, then I'd go with 4. The others are less consistent in the use of curves and angular lines.
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.
This is copy&pasted from HERE ... sounds good to me.
1. Keep your watermark simple and monochromatic. (No colour and minimal use of graphics.)
2. Keep it as small as possible while being legible.
3. Use a vertical watermark. It is still legible but the viewer won’t get distracted trying to read it every time they view the photo.
4. Put your watermark on the edge of the photo.Yes, it’s easier to crop out, but it serves its main purpose and those that want to remove your watermark will remove it no matter where it is placed.