If the band toured in the '80s I saw 'em as a friend's dad operated a Ticket outlet. I have quite the collection of tour programs and t-shirts too.
Bands I've seen more than 10x
Maiden over 20
Priest (2nd concert ever was the last show of the Vengeance tour in '83 in Honolulu with my parents)
Black Label Society
I've also been to the Monsters of Rock in '88 where Metallica was sandwiched inbetween Kindom Come and Dokken,Crue opening for Ozzy's Bark at the Moon tour (very rowdy show on both ends) and even saw an early Twisted Sister show before their Stay Hungry album broke.
The heavier metal shows I saw on the rare side include VoiVod,Mercyful Fate,Overkill,Grim Reaper,Raven and of course I've seen Slayer including their tour with Anthrax and Testement a bit over 20 years ago now. Boy time flies.
'12 Focus Red Candy SE Sport 5 spd
'99 Toyota 4Runner Sport
'11 Subaru WRX STI Hatch