Black Knight, Firepower, and Xenon. Our local Time Out arcade had BK and FP in the back right next to each other, and my buddy Geoff and I spent untold hours on both. We would coin up two-player games on both and then swap machines mid-play. Xenon, in the same arcade, was set up pretty loud and at the time I absolutely detested that game just for its sound effects. Nowadays it's at the top of my want list.