Quoted from StevenP:Spirit of 76, at the front of a department store (Zayres, I think). Watched a couple of kids play, and tried it myself. And then when I discovered MIT's game room (full of glorious EMs) while in high school, I was hooked.
Ok, so anybody else from that area, J.M. Fields in Natick had an EM 40 years ago. It had at least one red pop bumper cap up towards the upper right side of the playfield. That was the game that hooked me, but I have no recollection what the game was 4 decades later.