I usually don't wear a hat. Sometimes I do, out of necessity, like wearing a "boonie" hat when it's sunny and I want to protect myself from the sun, but usually I go hat-less. I think it has to do with being unable to find hats in my size usually since I have what's described as a "tank head". In the past couple of years though, I've discovered that I do like a certain type of hat (and can find it in my size), the Newsboy. I really like wearing them and Ami thinks I look good in them (that's all that's important really).
Here are the two that I have.
The one on the left is wool and it's very warm, almost too warm sometimes. The one on the right is made from cotton twill. It's very comfortable and isn't as warm as the wool one. I'd really like to get one in a gray herringbone pattern but they are a little hard to find in my size: tank.