For me it was Freddie Mercury's tribute concert. I was sixteen or seventeen and we watched it on a video wall in a disco next to the place I lived then. It was amazing. Now when I watch this particular GN'R performance I can't say it's the best eva but back then I was impressed. Axl's attire is undisputably one of a kind
And he and Elton John make a nice couple 
the freddie mercury tribute was one of mine too, my dad was a session guitarist in the 70's and had met, jammed and got blind drunk on a handfull of occasions with queen before they blew up! I remember very clearly watching tv with my dad when it came on the news he had died.
Seeing guns on the tribute gig was the first time i had heard of them and i have loved em ever since.
