So many to choose...
I would say the Saturn outside of Japan, really a great console with great games.
The Wii U had really great games, but it didn't help the console at all.
However the PC Engine/Turbografx 16/GT, and especially it's mid-gen upgrade Supergrafx, is my "winner" here. So many great games, great tech, great visuals, not expensive (except for the Super and the portable GT), yet so paltry sales with less than half the sales of the Wii U.
The Nintendo eShop rating Thread: http://gamrconnect.vgchartz.com/thread.php?id=237454 List as Google Doc: https://docs.google.com/spreadsheets/d/1aW2hXQT1TheElVS7z-F3pP-7nbqdrDqWNTxl6JoJWBY/edit?usp=sharing
The Steam/GOG key gifting thread: https://gamrconnect.vgchartz.com/thread/242024/the-steamgog-key-gifting-thread/1/
Free Pc Games thread: https://gamrconnect.vgchartz.com/thread/248138/free-pc-games/1/