What's the Best Cardio Machine?

The New York Times asked 10 experts to choose a winner among the treadmill, stationary bike, stair climber, ellipitcal trainer, and rowing machine. The elliptical trainer won by a large margin.

"Our 10 experts thought it had many virtues, chiefly that it allows a low-impact, high-energy workout that is fun. Used correctly, an elliptical trainer works the muscles of the central core as well as the lower body, although some experts think research is needed to determine how hard a workout its users really get."