I saw all of these bands in their prime (and since), so I really feel no need to go out of my way to see them now.
Anthrax - 1989, State Of Euphoria tour (Newcastle City Hall)
Slayer - 1990/1 (???), Seasons Of The Abyss tour (Newcastle City Hall)
Megadeth, 1990/1 (???), Rust In Peace tour (with Alice In Chains supporting, f*ucking great), (Newcastle City Hall)
Metallica, 1991/2 (???), Black album tour (Whitley Bay ice rink)