Ok, admittedly all metal (I listen to lots of different stuff, but I live for metal) - but I saw a few hard entries already, so...
Destruction - the original Mad Butchers, none can match their mastery and energy. They're back!
Queensryche - repeatedly wiped Metallica off the stage during the Operation Mindcrime / And Justice... tour. What a mismatch.
Megadeth - Rust in Peace tour, anything newer is dross. Mustaine back on planet Earth briefly, Marty Friedman's in.
Coroner - thanking my lucky stars I saw these techincal killers before they called it a day.
Saxon - never quits, never fades. Stronger than ever, once again in the new millenium. They've got Wheels of Steel!
Demolition Hammer - none but the hardcore would have seen these guys, but holy hand-grenades Batman! Still love the memories from these shows.
Now, just if Venom would stop by my little neck of the woods!
Mike