Townshend for speaker wire and interconnects. No question. It sounds a lot better than anything else I have tried. HFC has impressive speaker cable in its upper ranges, their ’entry-level’ wire was less impressive.
Phasure and SOtM for Ethernet cable. For longer lengths cheap cord from Kasimo cat 8 and FS.com cat 8 is pretty good too, especially for the price.
CAD and Phasure for USB cable. Low cost Supra USB is not bad either if cost is an issue.
Supra for subwoofer cable.
Van Damme for XLR - really cheap studio wire which is top quality. And to my ears sounds better than many audiophile brands.
Van Damme for 75 ohm sine wave master clock cable. Again very cheap and very well made. I could not hear a difference between this and expensive cables. It was not better, just not different. I am not sure re square wave clocks as I understand that they need a more rigid expensive cable.
Power cable - Shunyata and MCRU. Naim makes a good value mains cable. Nothing else has really made a significant difference to the sound for me.