Not the rarest but probably the most curious gadget by Nintendo. I owe one of those and, every time I bring it to a show, it gets a lot of attention.
Sega Genesis Repair VHS by Irata Systems
Hidden StarFox Flight Jacket
Off Your Rocker Amiga Atari 2600
Xbox 2001 Launch Team
Atari Product Tapes about Gauntlet Legends, War Final Assault Road Burners, Vapor TRX/ Site4, Area 51 Hard Drive service,Radikal Bikers (copy-paste from auction)