As laughable as it sounds, the Sega 32X. I was a Genesis kid and one birthday my parents bought me Star Wars Arcade not understanding that it required the 32X to play. I kept telling them that the game wouldn’t work without it (even showing them that it wouldn’t fit in the regular Genesis slot) and they kept insisting that I must be doing something wrong or that I could just cut the corners off the cartridge to make it fit. So I wanted the 32X to play Star Wars, as well as this strange Knuckles game I kept hearing about (which I know is Knuckles’ Chaotix). Never ended up getting one. Got an N64 soon after, much better decision.