Which material is known for having the best conductivity?

The material recognized for having the best conductivity among the options provided is copper. Copper is widely used in electrical wiring and components due to its excellent ability to conduct electricity. Its atomic structure allows for the free movement of electrons, making it highly effective for electrical applications. This property is why copper is often the preferred choice for electrical conductors, outperforming other materials like rubber, plastic, and even other metals in certain contexts.

Rubber is an insulator, meaning it does not conduct electricity effectively, while plastic shares similar insulating properties. While metal wire might indicate various metals, none compare to copper's exceptional conductivity in practical applications. Thus, copper stands out as the optimal choice for electrical conductivity.