Tell us about some of the ones you've seen. Here's five of mine.
Wire Train, opening for Big Country, Ann Arbor, 1984. The only time I've ever seen an opening band get an encore, and goddamn did they deserve it.
Peter Tosh, opening for The Police, Toronto, 1983. He torched The Police, and they were shit-hot themselves that night. Tosh was just on a whole 'nother level. 2nd to last show he ever did.
Gregg Allman, opening for Stevie Ray Vaughan, night 1 (I saw them 2 straight nights), Detroit, 1987. He didn't try to out-firepower SRV; hell, I think half of his show was ballads. Dude brought sexy back, and I think that was the last thing anyone there expected.
Flaming Lips, opening up for Candlebox, Detroit, 1994. I went to the show with three friends who were total Candlebox fiends at the time. All we could talk about for days afterwards was the FL's performance. They were like from fuckin' Mars.
Ben Neill, opening for Transglobal Underground, Detroit, 1998. Like Miles Davis gone techno, in the best possible way. Damn, did he ever get that party started right.
Sabaton, opening for Amon Amarth, Detroit, 2013. Absolutely hated them before I saw them. It's not like I'm ever gonna go get their recordings, but I'll see them any chance I get.
...well, there's six of them. Probably post some more picks later.