I don't listen to metal in order to scare myself or people around (it was maybe the case when I was a teen, searching for the heaviest and scariest bands around, which were Sodom, Possessed, Destruction, Slayer and the likes, but it's not the case anymore).
I like heavy guitars, nice riffing and good melodies, with clean vocals (or I should say no growls cause I enjoy a band like Grave Digger and the vocals are surely not that "clean"). That's heavy metal for me. Volbeat is metal, Dio is metal, Slayer is metal, Pretty Maids is metal, Dream Theater is metal.
The problem is that the definition of metal changed over the years. What was "heavy metal" 20 or 30 years ago is now classed as "hard rock", while "heavy metal" is reserved for the heavier bands with extreme vox. That's bullshit as far as I'm concerned. Judas Priest or Nocturnal Rites are as "heavy
metal" as Soilwork or Cannibal Corpse or any extreme band for me.