With a suit, I wear an ambassador (also known as a diplomat and similar to a cossack). It's a russian hat usually made from beaver fur or lambswool. It's a perfect dressy hat for Pennsylvania winters. For more casual occasions, I wear a boina (actually, a Hoquy beret...I've seen them as low as $36) or a plain old skullcap. I believe berets were usually worn by English schoolboys and not very often in France anymore. That being said, ignore people who laugh at the fact you wear a hat (sheesh) in sub-zero temperatures--they're idiots.