The list provided by ricred1 is pretty accurate although there are some others, such as the Totaldac USB cable/filter that have their followers. I own both the Curious Cable and the Totaldac USB cable/filter and I prefer the Totaldac.
BTW, regarding "heads and shoulders above the rest," the sound of these cables is system and user dependent. Also, there are many methods of getting your digital music to your DAC and there isn’t even universal agreement on the best way to accomplish that. Throw in add-ons such as the various in-line reclockers and linear power supplies and you are left with a basic crapshoot. You really need to listen for yourself.
BTW, regarding "heads and shoulders above the rest," the sound of these cables is system and user dependent. Also, there are many methods of getting your digital music to your DAC and there isn’t even universal agreement on the best way to accomplish that. Throw in add-ons such as the various in-line reclockers and linear power supplies and you are left with a basic crapshoot. You really need to listen for yourself.