10. Segway (2002-?)

To fans of the Segway, the famous two-wheeled, self-balancing electric vehicle is far from a flop. However, because it was so hyped at launch, with promises of changing how we live and build cities (Jeff Bezos said it would be "one of the most famous and anticipated product introductions of all time") many view its niche-status in the marketplace as a major disappointment.