The Super NES CD-ROM (aka the Nintendo Playstation)
While the Super NES CD-ROM was originally supposed to be a collaboration between Nintendo and Sony when it was first revealed back at CES 1991, any plans to actually make the thing quickly dissolved after Sony discovered that Nintendo was also in talks with Sony rival Philips to help produce its hybrid cartridge/disc-based console. And while around 200-300 Super NES CD-ROM prototypes were produced, only a handful of those prototypes have been spotted since then, with one lucky model having sold at auction last year for a cool $360,000.
After breaking up with Nintendo, Sony took the idea for a disc-based console and turned it into the original PlayStation, which went on to change the console gaming landscape forever.
