I have tested a number of Ethernet Cables:

Audioquest
Chord
Meridian SpeakerLink
No name UTP
No name STP

Audioquest and Chord are expensive.

I could hear an improvement if the Cable was unshielded or not but all shielded Cables sounded very good.

861v8+ID41, HD621, G98, Arcam P35, DSP7200SE, DSP7200HC, SW1600, DSP320.
2xMS600, 2xMS200, 2xDSP3200, AC200, Explorer2, 2x218, AD88, Prime, 251, 210