Iron man skill shot with the outer post disabled. With the post enabled it's the easiest skill shot in pinball. With it down the ball either falls short or just keeps on going. Not sure if from the plunger counts but it's pretty difficult. Also the away team/mission select shots in Star Trek ( more of a personal issue as I think it's just me… flailing 30 shots before loosing it and only getting 3 missions per game).