Came across this interesting little list today. I still haven't heard of most of these bands, but there are some good ones on here.
http://www.u2interference.com/forums/f288/history-of-u2s-supporting-acts-98944.html
Zoo TV really sticks out there. The recent parade of shit support acts has a long history. Hell, even by Popmart they got Smash Mouth - Smash Mouth! - to support them, and some of their eighties supports are really fucking questionable too.