Chiming in with a recommendation for Darwin as well. Started off with ArgentPur, it was great (I had speaker cable and prototype RCA). I wanted to see if there was something similar in quality at a slightly better price. Someone on another forum topic had recommended Darwin, I checked them out and tried out one of their demo Truth II speaker cables.
To me, it sounded on par or perhaps even better than the ArgentPur (and they are great, don't get me wrong!). So I tried some more: IC, power cord; both gave me the same improvements.
That was a few years ago, and I just got the latest delivery (my second set of Enlightenment speaker cables) yesterday. Across several systems I now have Darwin cables in most. Power Cords are Darwin and others mixed (TG Audio, Puritan as well). But all IC's are Darwin (Truth II, Natural, and Enlightenment), and speaker cables are a lot of Darwin: Enlightenment in 2 systems, the ArgentPut in one, and Darwin Truth II (occasionally Black Cat Silverheart, a model created just before thew current line) in one as well.
The Darwin cables are not harsh, though if the recording or gear leans that way it will certainly expose it. What is non-typical of these is that the bass control and extension is incredible; they are definitely not lean-sounding. Top to bottom balance is the best I've heard, and the details within the stage that they bring out pull me right into the music.
Definitely recommend Darwin strongly. Also recommend ArgenPur too like grk above; especially if you can get a good deal. I found in my systems that Darwin was on par or better for less money though.