If you ask me, the Mattel HyperScan.

I remember being excited about getting this for Christmas when I was younger. When I got it, I set it all up and started the console, only to be disappointed.

The cards barely responded, and had to scan them in a certain way, which was beyond frustrating. I only had two games for it: X-Men and Ben 10, both which were god awful.

When I was finished, I unplugged the console and put everything back in the box, never to play it again.

Can you top that?