There is always a certain 'style factor' in parting an opponent's head from their shoulders, preferably with an accompanying "blood geyser".

Even better, you get to follow the trajectory of said cranium as it falls earthwards, and even perform additional defacements to it if the situation seems to warrant it.

Special effects departments have traditionally loved this type of death, as it was a great excuse to fashion gruesome latex models. These unconvincing mannequin heads are seen less frequently since the advent of CGI though, which we feel is a shame.