Quoted from Shoot_Again:Flash Gordon is the oldest machine I can think of with a skill shot. Maybe start with 1979 forward.
It wasn't advertised as a skill shot, but Fireball had one almost 10 years earlier. It was very strategic (valuable) and not easy to do without practice. If you have to play Fireball in a tournament, by all means try to get in some practice time first to practice the skill shot.
Fireball also had multiball, zipper flippers and a spinning disk. If ever there was an LE EM, Fireball was it. It ruled the arcade around here for years.