I've got a short list of all time faves...here it is:
Morbid Angel: Blessed Are the Sick
Metallica: Master of Puppets
Iron Maiden: Somewhere In Time
Tangerine Dream: Ricochet
Mahavishnu Orchestra: Birds of Fire
Metal: very very hard to answer but I can say Moonspell: Wolfheart.
Non metal would be... hmmm... Queen, any of the three greatest hits. Or Diary of Dreams: Gothic Enigma II [yes, I like some gothic bands I'm ashamed to say ]
Gothic music is nothing to be ashamed of, on the contrary! many bands woulndt sound so good with gothic inspiration, weather it taking from gothic metal (mdb for example) or old gothic rock like the Bauhaus or the cure.