Hey there,
Just thought I'd lend my experience to this discussion. Several years back when my system was real basic, I tried out some nice rca cables far outclassing the quality of components and was floored at being able to hear the difference. As my system progressed, I tried some even nicer usb and rca cables and again couldn't believe the level of improvement. Last week I was doing a cable demo and set things up for my dac and popped in a cheap power cord because I didn't feel like grabbing my regular nice one out of the other room. Big mistake, as I immediately could hear a crappy, harsh, grainy sound. I quickly swapped in my proper power cord and fired it back up and just laughed at how much nicer things sounded. Very, very audible improvement. Point being, if you have decent components and speakers, pairing them with quality cables is an absolute improvement. Think of the cables like tires on a car. If you were to have a race car, would you put tires from a Prius on there? Probably not. On the flip side, if you were to put soft racing slicks on a Mazda Miata, you think it'd be an improvement on the track? Heck yes it will. Can everyone tell a difference in how their car drives with different tires? Probably not.
After lots of demo cables through my system, I've landed on Hapa Audio Aero Cu usb cable, Hapa Ember rca, GR Research B24 power cables, and next is GR Research 24 speaker cables. Each and every one of these cables have been a major step up in quality of music reproduction that improve every aspect of sound in my system. I've heard some very nice other cables through here as well, but they surpassed what my wallet is comfortable with. Lol.
In my system, I've found that I prefer good copper cable over silver in most cases, but there are a few silver cables that bring something special to the party. I recently did a demo of Empirical Audio new Kloud 9 rca cables and was thrilled at the level of detail and soundstage from them without any harsh edginess. I guess my point is, have fun and try some stuff out. Buy from smaller cable producers as your quality/cost ratio will be far higher and likely have a good demo/return policy. Listen to your system and try to see where you'd like an improvement. Is the soundstage kinda flat and you wish it were deeper, more 3d? Do you wish you could hear some more detail in plucked guitar strings and drums? The really nice cables should be able to bring a good bit of everything to the table in quality tone, improved details, increased dynamics and bigger soundstage. Giving yourself an idea where you'd like to go should really help direct your purchases to be big wins rather than trial and error.
Hope this helps,
-Lloyd