The early 80s post-punk period was pretty ace, but that might just be because I was 14 in 1980 and going to loads of great gigs in Liverpool, so I'm kind of biased I guess. All that NWOBHM stuff was bloody awful though, as were all those dire cliché ridden American poodle rock bands. The charts did seem to be more eclectic then though, which was generally a good thing.
I think Live Aid killed the traditional music industry as was, that and the introduction of CDs, which gave the industry an opportunity to endlessly re-package everything instead of focussing on new talent. I don't personally think it has ever or will ever recover, which is possibly why my own tastes have drifted further towards left-field and world music. Or is that just what happens when you get older? I dunno...