The first I went to on my own at 14 was Sabbath, with ... Journey opening. I think ACDC was next opening for Tad Nugget. They blew the hack off stage....
I had friends who were disc jockeys, and another who was a promoter. Through most of the 80's I had back stage passes to almost every show. I saw a lot of crappy bands ...... and even more 14/15/16 year old groupies.
I still think the best show in quality was a sober SRV in an acoustically sound auditorium with a great soundman. Neil Young with Crazy Horse would be next, then various (too many) deadshows. Dead had some of the best sound engineers on the planet in their time. I also saw SRV when he was still binging, which was one of the worst shows I'd ever seen.
People underestimate and undervalue the sound engineer.. he is the filter that the band goes through before the music reaches your ears. Having a good soundman is the difference in a quality concert and a horrible sounding one.
fwiw - 90% of live rock acts sound like pure shit, only went for the party.. I don't blame them, I blame the sound engineer.