After looking through your skins I'd say I like Ninja babe and black and grey the most. (I don't know if you made Ninja Babe or not).
An important thing to remember is that less is more when it comes to skins. I think today more than ever, people want to look at something clean, streamlined and easy to navigate.
Background images are tricky, and I'd say most backgrounds in "cause and affect" don't work well, but as long as it's not your default theme it should be okay to have a skin like that because some people like it. The Ninja Babe background was fine though, because the image is more subdued and the rest of the skin colors actually matched the image.
"I'm so blue" hurts the eyes, as others have said. That electric blue with black just never works.