My favorite is audiophile network switches. Never mind the fact that two devices connected with RJ45 ethernet have no direct electrical connection since signalling is done via transformer coupling, so it is impossible to have a ground loop. Never mind the fact that it is a digital signal and audio streaming has robust error correction via TCP.
For the low, low price of $3800, you can be the proud owner of an audiophile grade, 100Base-T network switch: https://innuos.com/phoenixnet/
For the low, low price of $3800, you can be the proud owner of an audiophile grade, 100Base-T network switch: https://innuos.com/phoenixnet/