Don\'t bother with most of the 80\'s rock, at least not that idiotic metal scale cranking that used to be popular back then. Of course there were always individual musicians who put out records that were worthwhile, and I would say AC/DC was one of them. My favorite guitar player Stevie Ray Vaughan recorded almost all his records in the 80\'s, so you can\'t write off the whole decade. On the other hand, the majority of the music released now is crap as well. I think it\'s safe to say that the majority of music purchased by many people is crap, no matter what time period you\'re looking at.
It\'s good to have guitars of many different types so that you can pick up the right one to learn whatever type of song you want to play. You should have an electric, a 6-string steel stringed acoustic, a 12-string, a nylon stringed classical guitar, and maybe a few other oddballs thrown in.
If you all want to hear some real guitar playing, then buy records from these people:
Leo Kottke
Doc Watson
George Benson
Mahavishnu Orchestra (featuring John McLaughlin)
Buckethead and/or Praxis
Captain Beyond (featuring Rhino)
The Allman Brothers