... WHAT POWER CORD(S) ARE PLAYING IN YOU SYSTEM TODAY?

I'm not sure if one strand of copper is better than another, but what I do care about how well a power cable is shielded. I've have had some pricey cables in the past but they did not pass this simple voltage meter test as described here: 
https://www.youtube.com/watch?v=UVn7UsaDmcQ
I since sold those expensive cables and went exclusively with Pangea for this reason.
They sound fine as well.

All Oyaide Tunami (GPX, GPX-R, GPX-R V2)

Shunyata for ML speakers and Krell Vector HC for Krell monoblocks. 

Analysis Plus

Mostly Nordost mid level offerings.
I spent years poking fun at the whole idea of ridiculously high priced wires and still feel that way for the most part.
The big change for me was when I swapped out stock cords on my amps and I had to eat crow. I was eager to tell my buddy who brought them over that I heard no difference but I did.
Bass was much fuller, highs were less grainy were the 2 most pronounced differences I heard without question.I had to rerun room correction to balance the sound again as the bass was so much fuller. Not bloated or muddy, just louder and more prevalent.

Scott