Iron Maiden, Dream Theater, Van Halen, Tool, Opeth, Ozzy Osbourne, Dio, Metallica (before Black Album. More specifically, the songs Mustaine wrote), Death, so on.
I think a lot of bands tend to bastardise the term 'music' in metal. They make songs with the mindset of "oh, I want to be awesome" or "oh, that sounds cool, whatever" and they don't really write much worth listening to. You listen to greats like Iron Maiden, Dream Theater etc. and you can hear just how definitively important the instrumentals are, and generally a story or deeper meaning behind the lyrics. The instrumentals complement the lyrics of the song, so it's not really "oh, that sounds cool" but rather riffs, melodies and so on were written to complement the actual song.
Personally I think that's why there's a dividing line between people who like metal and people who hate metal, with a very small middleground; a lot of people / bands just don't think about what the song actually means, and they make it generic.