Timex Ironman Run Trainer GPS

Catering to pavement pounders, this watch tracks interval workouts based on every parameter you'd want (pace, altitude). Its heart-rate monitor is incredibly accurate, and testers loved its programmable nutrition alarms, which, when set, reminded them to eat and hydrate at the appropriate times. But it's tough to tweak midrun, and its GPS was spotty at best. [$275; timex.com]