Nike Fuel Band
The Nike Fuel Band is now discontinued, which makes it a definite addition to this list. Though it had a sleek design, the information gathered by Nike was incompatible with anything but Nike+ products, and it didn't always show accurate data. In April, the company fired the majority of the Fuel Band team and discontinued the fitness tracker. They had announced plans for a slimmer version due out in the fall, but that was cancelled too.
See the ZDNet/TechRepub