To me, the most important thing is a quality lens, and many companies fit the bill. I have a pair of Maui Jims, a pair of Costa Del Mars, and a pair of Oakleys. All are quality lenses, but I use the Costas almost exculsively for fishing for one reason, the lens color. For my eyes, copper (or vermillion as Costa calls it, just sees through the water and enhances green (veg) better than the others I have tried. Many lens colors enhance contrast (copper, amber, rose, bronze, yellow, certain greens), but for fishing, I have found the copper/vermillion colors to be the best.
I really like the lenses in kaenon sunglasses, but couldn’t find any that fit my head reall well. Plus, they were quite $$$$.