In data centers, Category 6A (Cat6a) Ethernet cables are considered the best option for high-speed data transfer.

Cat6a cables have a higher bandwidth capacity and can transmit data at speeds of up to 10Gbps over distances of up to 100 meters, making them suitable for high-density server environments.

They also have improved crosstalk and noise reduction capabilities, which helps to minimize signal interference and ensure reliable data transmission.

It's important to note that the choice of Ethernet cable also depends on the specific requirements of the data center, such as the length of the cable runs, the number of devices connected, and the type of network equipment used. Consulting with a professional network installer or engineer is recommended to ensure the best cable choice for your specific needs.