I love that it's vintage-style, reminiscent of those 20's flapper hats. You can even buy clips (such as feather, bow or flower clips) and attach it to the side, or just go plain. I like to wear it with a dress and red lips at night for a romantic look. And most of all, it keeps my hair neat on windy days!
Possible the best winter wardrobe item in existance - comfy, warming, classic and it can either compliment your face shape or cover a bad hair day (because we all have them!)
Plus the fact that you can completley make an outfit without breaking the bank, as you can find them cheaply anywhere. In my opinion, the little black hat (or LBH) should be right up there with the LBD as a must-have-will-completely-die-without fashion item.