One of my new favorite hats to wear, especially in cooler weather is the flat cap, or the Irish cap. They are comfortable, warm and do a wonderful job keeping the rain off you.
They can come in many shapes and sizes from the basic flat cap to the puffy and somewhat larger newboy cap, these hats are truly an original and in my opinion making a come back.
Maybe it is perceptual vigilance, but I seem to be seeing these everywhere. They are dressier than a ball cap, but not quite so high and might as a fedora, bowler, or stetson, other hats that are appropriate for various forms of dress.