Pippin Flops
I'm proud to say I once worked on this project, now honored by Wired as one of Apple's most notorious flops:
The big lesson I learned is not to stick with a product that you don't use yourself. Pippin (named after a type of apple) was supposed to be a multimedia machine for kids, but people in our group couldn't get their own kids to use it. The funny thing is that focus groups loved it -- another reason I don't trust focus groups.