Silver is the most conductive element. However, it is not often used to conduct electricity because it is more expensive than copper and tarnishes more readily than gold, particularly in environments that contain sulfur or ozone.
Copper is the second most conductive element, and gold is the third, when comparing by volume. However gram for gram, aluminum wire is more conductive than copper, as it is significantly less dense than copper. It is less reliable as well, as it deforms more readily and can form a resistive oxide, which heats up when electricity is passed through it. Most metals conduct electricity readily.