I used this:
http://www.monstaliner.com/
Its tough as nails and comes in 39 colors. It has a slight texture when not backrolled and a satin sheen to it. I really like it.
It is not cheap though, you could do Awlgrip for the same or less but I wanted no worries about scratching it up and I didn't want to spend a couple hundred on a rub rail either. Its been into the dock several times on windy days without a scratch.
A couple of pics of the texture:
Edit: The only negative I can say about it is that decals don't stick very well to it as you can see in the first picture. I'm not sure if its the decals or the coating...