What makes phono cables different?

IMO, the difference in phono cables has to do with the loading on them. If the cartridge is designed to be flat into a certain capacitive load, then the combined cable and preamp input capacitance should match this capacitance. I have seen cases where cartridges did not sound good when the capacitance was too low or high.

Quiet is probably the most important issue, but in general it's similar to regular interconnects, except now, due to low signal, the sensitivity is much higher. Most of my sytem is Audioquest cables. I have heard the emerald phono cable, the Hovland, but settled on the Siltech. The Siltech has an unusual grounding scheme. All connectors can be independently grounded, instead of just having one ground wire. This cable was considerably more quiet than the others I had tried.

The quality of the connectors and sheilding makes a difference since it's carrying very small signal. Listen for background noise and hum with the tonearm lifted.

I have found Audioquest Anaconda and Amazon to be very quite.