The best digital cable I’ve heard--and the last one I bought--is the Oyaide DR-510. Price is under $300 for a length under 1M. I got the 1.3M. Note that the same cable can be had with BNC terminations (that one is DB-510).
The DR-510 sounded noticeably better than the previous digital cables I used, so much so that I never stopped using it in my main system. Currently it carries signal from a DDC to my DAC, the MHDT Labs Orchid.
https://www.thecableco.com/cables/digital-cables/digital-spdif/dr-510-db-510-digital.html