Motörhead and Y&T were semi-regular opening bands down here and were always fantastic.
Roudness
I'm having a hard time coming up with the "best," but I feel like I'm drawing a blank on some obvious choices. But here are some honorable mentions:
-Warrant opening for Britny Fox. Warrant were unknowns at the time. Their first album had not yet dropped. But they were about to become huge and the label knew it and was trying to get them out on the road and get exposure. They had a TON of energy, were great showman, and had a tight performance.
-Tesla opening for Def Leppard. Already mentioned, but they were a fantastic opening act.
-DT opening for Satch/Queensryche. I feel like I'm cheating here because these were "co-headlining" shows. And it's DT. But still.
-Trivium opening for DT. They didn't steal the show, but were REALLY good.
-Whitesnake opening for Motley Crue ('87/Girls, Girls, Girls tour). This was a Day On The Green show. 'Snake was in their prime and had Adrian and Vivian on guitars. They slayed.
-Kick Axe and Whitesnake opening for Quiet Riot (Vices, Slide It In, Condition Critical). Both openers were really good, and I became a fan of both bands that night. And although it would take me years to appreciate what I had seen, it was cool to have seen Sykes in Whitesnake.
-Faster Pussycat opening for Whitesnake. Said no one ever.