First and foremost its a matter of personal preference as regards any users individual rating. For a skin to achieve a 5 star rating it requires something special. There are only seven 5 star skins on the skins page currently and of those only XDJ and Alexis have more than 10 votes. In both of these skins I'd say that the high rating is due to eye-catching and innovative design with clever use of animation.
Functionality, usability, design and innovation are the main reasons for a high rating, it's wonderful when a skin has all these properties. There are quite a few skins for which I awarded a high rating that I hardly ever use as I prefer functional skins that don't get in my way even though the skins look great and are fun to use.
The downside with the rating system is that it only works if people bother to vote on the skins. I have a bad habit of just ignoring skins I don't like the look of whereas I really should give them a rating.
I voted on your iSoundSystem skin btw fox619
