You gotta read this story about the accidental finding of a very rare game console prototype developed in the late '80s by Nintendo and Sony. The game console is dubbed the "Nintendo PlayStation" because it supports both Nintendo SNES/Famicom game cartridges as well as optical discs (which were later used as the main game medium for the Sony PlayStation).
Engadget interviewed the owners of this mysterious device at a Hong Kong retro gaming expo. The owners, Dan and Terry Diebold, got their hands on this thing after the company the father worked for, Advanta Corporation, filed for bankruptcy and auctioned off everything to whoever wanted to pay. In one of those auction boxes was this gaming gem. It is reported that only 200 were ever made (who knows how many actually still exist!).
Polygon has the full story of how this game console came to light, thanks largely in part to reddit's obsessive gaming community.