Digital cable...

+1 for Blackcat Silverstar 75. But, if you can find a used Stereovox Reference XV-Ultra (same guy who runs Blackcat, Chris Sommovigo) it is a level up from the already very good SS 75. I think I paid $250 for mine.

The best S/PDIF coax that you can buy at any price is the BNC-BNC 4-foot cable with RCA adapters that Empirical Audio sells for only $250. It beats cables costing 10X. Only the best pure silver and expanded Teflon technology.

This cable has been in shootouts with the best S/PDIF cables on the market and always wins. I have many customer feedbacks posted on forums confirming this.

Steve N.
Empirical Audio

Some good options listed above. I'll just chime in because I've got the Stereovox XV2, which is related to the Illuminati and Blackcat as it's from the same designer. It's a very transparent and very detailed digital cable, so if you're looking for more clarity and detail out of your system these may be good cables to try. If your system already leans to the, um, lean side they may not work for you, although the Blackcat my be different -- I haven't heard it.

I also have an Apogee Wyde Eye that I tend to use most of the time. In my system it sounds a little more balanced and natural and less tipped up in the highs than the Stereovox yet still nicely detailed. You can get a 0.5m Wyde Eye cheap at music stores (i.e. Guitar Center, etc.). Hope this helps and best of luck.