What is so special about Saxx Underwear?  Their Ball Park Pouch™ reduces friction, and ,as the Saxx website explains, keeps "man-parts" in place.  In two words they are "unbelievably comfortable".

Other features: non-chafing flat out seams™, moisture control, soft 4-way stretch fabric with odour control. 

The cat's pajamas of men's underwear.