I've become a fan of Tilley hats. I bought my first one because I just couldn't find a nice had big enough for my giant mutant head.

For summer I use a Tilley LTM6 - with the mesh panel around the top and the wider brim.

For winter I use a combination of Carhartt knit hats (I like the blaze orange ones) and a Tilley TW2 Winter Hat. I like that the brim of the Tilley hat keeps the falling snow off my glasses, plus it has an ear warming flap and a forehead warming flap.

I was kind of surprised to find that the Tilley TW2 Winter Hat is dry clean only, though I've yet to need to clean it.