The bowler hat is a hat. It is a rounded hat. It was mainly worn by gentleman but isn't seen often these days, although they are still in use especially in parts of South America.

The bowler was the hat of choice for Charlie Chaplin and Laurel and Hardy.

John Cleese suits a bowler hat and looks lovely in one.

Winston Churchill often wore his bowler when out in public, especially in his later years.

Therefore the bowler hat is likely the winner.