I went to the bottom of pinside's top list and found the 16 lowest ranked mainstream games (no boutique or special order games). This is round three of this poll, with 4 games remaining. I'm bummed that AMH beat out The Avengers. It is, IMHO, the worst mainstream machine of the last decade.
Round one can be found here: https://pinside.com/pinball/forum/topic/worst-pinball-machine-in-the-last-decade
Round two can be found here: https://pinside.com/pinball/forum/topic/worst-pinball-machine-in-the-last-decade-part-ii
Remember that you are voting for the worst games, each one that sucks more than the other that it's paired against.
