My answer: None of the above.
The worst Nintendo console by far was the Virtual Boy. Why?
1. It wasn't even in color, unless you count red. Everything was red, and ONLY red.
2. It gave people headaches.
3. It had no games that were worth the purchase.
4. It was discontinued in less than a year.
5. It was such a huge failure that I've heard the designer was demoted. He's also dead now, but that wasn't the Virtual Boy's fault...OR WAS IT?

Seriously, all the consoles in the poll are masterpieces compared to the VB. People like to point to Sega as the poster child for bad console ideas, but I'd take a 32X over the VB any day. I'm dead serious.