Say goodbye to tighty-whities. The latest streamlined boxer-briefs offer comfort, support, and an elasticity suited to men who lead active lives. But not all performance skivvies are made equal or for the same thing. A blend of performance-driven fabrics and more-athletic cuts mean that the same pair you put on to go to the office might not be the best choice for a workout or a trip. Our editors tested more than 20 pairs to pick the best for every activity.