I can only contribute to this post from a personal perspective moose.
'60s: Alice Cooper.
Even though it was the early 70s when I bought 1st Cooper album, the band was started in the late 60s. It was released in '74. I was 11.
I had read about the band in magazines and heard Rock n Roll all Night on the radio, but being a kid with a paper route, my album budget pretty tight. Albums were $7.29 + 6% tax at the Kmart. So I was browsing through one day looking for another Alice Cooper album, when I came across Kiss's "Hotter than Hell" priced at $2.99! Might have been a mistake but if so it was in my favor. I figured for 3 bucks I could afford the risk of buying an album I didn't like. I loved it! And until AC/DC came out with BiB, I was pretty much listening to Kiss.
Got nothing for the 80's. I was out of school and working, then married and the next 3 or so decades are a blurr.
I should add, AC DC became the only band where I have all the albums, even a bootleg album from the 70s. Bought just recently. But of course, they aren't American.
Thanks for bringing back some memories.