This may seem like a no-brainer, but I know of several people who don't do this. Always remove the skin prior to packing. Your fish will last much longer. The skin has an uncanny ability to reconstitute that slime, even after 6-8 hours in the smoker. The people that I know that leave the skin on do so because it continues to trap some of the oils between the meat and skin. I don't know whether there's any science to it or not, but I can guarantee your fish will last longer without the skin, especially when just refridgerated and not frozen.

-Jim