Cables are part of a system. Different systems have different approaches. Some systems are designed for heavier, louder music types (metal, rap, etc), whilst others are more subtle (for classical, blues, soundtracks).
That being said, a true Reference-Quality system is above and beyond the concept of accommodating for the recording. The Reference system neither adds nor takes away from the sound, it is simply not allowed to do so. The Reference system utilizes a minimalist design that assures the purchaser perfection in initial design, without need of compensation. This zero-compensation policy applies to cables as well.
A Reference system only reveals what is in the recording, exactly as the artist/composer intended the end-user to hear. The cables cannot interfere with the rest of the setup, they are not allowed. Only cables that neither add nor take away from the system can be used, so 'house-sound' cables, or cables designed to improve treble, bass, texture... you name it, need not apply.
This does not make cable choice any easier. I cannot say I have ever heard a Reference System. I don't believe anybody can say that, but I have heard the closest thing. And drawing from that experience (about 100 hrs. of listening), I can better asses cables to determine how close they come to Reference Quality (or, at least, how they compare to the closest thing I've heard to Reference).
In case you were curious, what I currently consider to be Reference Quality is a setup consisting of seven B&W 800 Diamonds, seven B&W DB1's, each bi-amped by McIntosh MC-2KW's, sourced and controlled by McIntosh. Everything is wired with Analysis Plus Golden Ovals. Power Conditioning handled by a Richard Gray's Powervault, stepping down from three-phase 600V.
I do not consider my system to be anything close to the system described above. I am on a budget and have undesirables to deal with (neighbors). I have to create quality without the volume. I use similar brands (B&W, Analysis Plus), but on a smaller and much less expensive scale. I am coming from a pair of Monster Cable M2.2s, retailing at $600 (I got them for $175 working at Best Buy!, and before that $20 Monster XP cable). I now have a $200 pair of Analysis Plus Oval 12's. Compared to the Monsters, they are much closer to Reference Quality, they take away less and add less. They are not perfect, but closer to my goals (not satisfied yet!).
Cables make an absolute difference, after changing Room, speakers, amp(s), and source. Then is when they are the next logical choice in sonic upgrade. I have found Analysis Plus to come closest to Reference so far, but have yet to test all products on the market. I want perfection, and it will come in due time.
"Strive for perfection in everything. Take the best that exists and make it better. If it does not exist , create it. Accept nothing nearly right o good enough."
--Sir Henry Royce, Co-founder of Rolls Royce.
Quite a few out there feel that folks that use ceramic fuses & the like for sound improvements are " Clinically Insane". I like these after market fuses and use them with my McIntosh amplifiers to great effect. :)