Optical Cable

Given that the transcievers are able to maximize to optical bandwidth as Nsgarch alludes to, the best sounding and extremely well-made cable IMO is a Van den Hul Optocoupler. I have used about a dozen different toslink cables, including the people's favorite (that cheap, poorly-made ebay $30.00 special). Nothing I've used is really close.

I just bought a Nordost Whitelight glass,very good construction.
George

For the money the Wireworld product is a very good choice. Yes, there is a difference even between glass cables. I got talked into trying a Cardas cable as a loan from The Cable Company and it cost several hundred dollars. To my own astonishment I bought it as it did sound better. Perhaps not 'several hundred dollars' better, but I am glad I did it.