Your first two sigs don't look good at all. The girl is positioned in a way that she is being forced to look separate to the sig itself. It's also not a clean cut around the image, so it looks very Messy.

The two green ones are better. They have a nice blend of colours and the layout is alot neater. The splatter one could be better if you were to use clipping mask in the coloured splats rather then the green. This will focus the attention more on the character, rather then some of the effects. Also, you might want to erase some parts of the splatter that are near her face, they do have an impact on the overall look.

Your last one just above is great. I can see a few additions that would make it awesome! You could add some small splatter clipping masks and it may to bring a bit of energy to the sig.