Shock, I actually saw Slayer in the early 80s, before I was even into rock really. Some chick took me to it on a date. Her brother played drums for the opening band, which was kind of a hair metal outfit. Then Slayer came on and people went nuts, scared the shit outta me. They covered Number of the Beast by Maiiden and I was convinced they were devil worshipers. Ha. I definitely wasn't ready for that shit.
This was in La Puente, CA in maybe '82/'83 at a Knights of Columbus Hall. Just a weekend gig for an up and coming LA band. I would have been so into it if it were 20 years later, but I was a f'n dork back then.