There's no doubt that stainless steel is one of the most universal materials for men. It's rugged, reliable, and can still be delicate when styled properly. You'll also find it's one of the easiest materials to maintain, especially for active men.
If you want a more elegant option, white or yellow gold is sure to impress, although it's bound to be more expensive. Sterling silver is another recommendation that glistens like gold but has a more affordable price.