I was ten in '76, so way too young to attend these gigs, but I loved the music when I first went to secondary school, and my mates' older siblings shared their punk collections, especially on cassette tapes - brilliant :)
I don't think music like the Pistols, Damned, Stranglers and the Clash will ever particularly "date" as they're just so good, along with plenty of other bands from the era too many to list now, but not to recognise there were tons of appalling bands that followed, which is the same in every musical genre once the creative souls have exhausted themselves/moved on.
The New Romantic era quickly followed, which I am quite fascinated by at the moment as out of it, and the ashes of Punk, came the Goth classics which young people would recognise today.
Bands like the Southern Death Cult, Bauhaus, Play Dead, Siouxsie, the Sisters of Mercy were favourites live, as well as on vinyl and in the clubs - anyone remember Berlin and Cloud Nine, as well as the Ritz of course (is this still going?) - these were all big parts of my later teen years, and so of course hold a lot of fond memories (even if many were proper cringeworthy).