Basis Band
Credit: Photograph by Plamen Petkov

The Basis Band is the data king: In addition to tracking steps and sleep, this smart watch-tracker boasts four sensors that continuously monitor your heart rate, temperature, and sweat levels. We liked how its app tracks your current goals (for example, walk 2,000 steps before noon) and adjusts them based on your habits. It's impressive but needs work: It wasn't as accurate as several others. [$200; mybasis.com]