I have a fleece one from Columbia that is my most important piece of cold weather comfortwear. Early morning cold commutes start with it up on the back of my head and up to my nose. As I warm up, it inches its way down. By the time I get to my train platform, if I'm warmed up sufficiently,. I stow it. If not, I wear it as a hat, with the top folded over till I board the train. If it's überkalt out, I'll have a smartwool beanie on my head and use the gaiter as a handwarmer.

I had a wool/polypro one I won from a British soldier a long time ago. It was better kit, but it eventually fell apart. Having the back of my neck warm while riding is very important to being comfortable.