I recently ran across the "movement tracking" category of devices like the Nike Fuelband, FitBit, and Jawbone Up. The Jawbone Up device works exclusively with iPhones (period! no website, no desktop app; nothing but iPhone) so it was useless to me, however I went ahead and purchased the Fitbit One and Fuelband devices.
I received the Fuelband two days after ordering, but the process for the Fitbit wasn't nearly as nice. It took almost three weeks before it finally showed up. Not a great opening experience.
The Fuelband is a bracelet whereas the Fitbit is a tiny device that can either be clipped on or put into your pocket. Both form factors have their ups and downs but I'll go into that later. I can already see that neither device will qualify as "better"; it definitely boils down to personal preference.