I detest salmon but whe I am forced to cook it for others I always start skin side down. I find the flesh does not stick to the pan as readily as starting flesh down and gives you a better chance to get the skin crisp/
Don't get me wrong -- I like the skin crispy, too. But if you start it flesh side down and don't move it at all, it will sear and not stick. Then, when you finish it skin side down, it will still get crispy and will be easier to serve.
I start it skin down, and do not flip. Instead, for a few minutes towards the end, I cover the pan. This insures the fish is not raw in the middle when I serve it. It is never over cooked. Also, I let it sit a few minutes before serving.