Kyuss -opening up for Danzig in 92.
The Reverend Horton Heat opening up for White Zombie in '93
Trouble opening up for Pantera also in '92.
Into Eternity opened for Opeth 2005. Great show.
I saw Vektor in August of 2012, with less than ten people. They played in an old funeral home across the street where I went to sunday school my entire childhood. The band that played AFTER them had like hardly anybody watching their set. We all drank beer with Vektor instead. In fact I still talk to Blake Anderson on FB occasionally.
Worst? STAIND opening up for Monster Magnet in '98.