I think different cable types also interact with different levels of equipment. As @soix said, a good digital cable can help any system or digital front end. Similarly, I have never heard a nicer power cable cause detriment, but always improve or smooth things out. Of course better equipment will reveal more goodness.
But interconnects and speaker wires can be detrimental. Silver cables (to me) tend to exploit glare and harshness. Nice copper cables are what I like, and they provide smooth resolution throughout the entire spectrum (Kubala Sosna Realization and elation for me)