Doom metal,traditional metal,etc..
You have bands like black sabbath,uriah heep,jethro toll,led zeppelin, mountain,deep purple,cream,ac/dc etc.. who are just as responsible also, these bands rocked with a harder edge with a who gives a fuck attitude that is used in metal.
Pentagram,saint vitus and candlemass after sabbath made some of the first really heavy cds that probably officially made doom a real genre. Bands like judas priest and maiden were bringing more regular styled metal that influenced power metal and even melo-death. Iron Maiden,JudasPriest really signatured the guitar playing and picking style used in metal to this day.
Trash and death metal are also influencial on the scene too.
Mercyful Fate pretty much brought all the dark lyrical themes to metal music influencing black metal and countless bands. I think specific bands infleunced metal over genres.
Without 70's music and these key metal bands we would not have heavier music plain and simple. Regardless there have been people defying and rocking since the beginning not always going with the grain.