This was mentioned already by Nicola, but the rare and expensive system deserves another glance.
The Adventure Vision was a handheld cartridge-based video game console released by Entex Industries in 1982. It’s often considered to be a failed system as it was a tabletop console that was much too large and fragile to be used effectively for handheld purposes.
Rather than using an LCD screen or an external television set like other systems of the time, the Adventure Vision uses a single vertical line of 40 red LEDs combined with a spinning mirror inside the casing. From what I hear, the thing DRAINS batteries in no time.
According to the auction, estimates are that only about 50,000 of them were sold, and only about 100 of those still exist today.
While there are only four cartridges for this system, those four games are all arcade classics, Turtles, Super Cobra, Defender, and an Asteroids clone, Space Force. This auction includes the first two.