My first concert was Iron Maiden and Judas Priest at the Meadowlandds in NJ in 1981 or 1982. Halford rode a 1/2 ton Harley onto stage during that show. When Priest did Green Manalishi the hair on the back of my neck stood up.

I've also seen Motorhead (used to be the loudest band on earth), Krokus and several other psuedo-metal bands like Blackfoot, John Butcher Axis and others I cant think of now.

The biggest surprise I got was seeing Jeff Beck live....dude plays very loud and heavy in concert.