The Sonoran Plateau Desert cables are very good, and very reasonably priced. They are commonly compared with the more expensive Transparent cables in sound quality. I have them on my system, and I find them to be very detailed and neutral. I think this qualifies for your "best kept secret" category, because I think the word hasn't really gotten out on these cables. Build quality is first-rate also. I think they are a high-value product, with great sound for affordable dollars.
Another possibility is the Purist Audio Venustas cables. They are a new line for Purist, and I have heard alot of good things about them from users. They are somewhat higher priced than the Sonoran.
Another possibility is the Purist Audio Venustas cables. They are a new line for Purist, and I have heard alot of good things about them from users. They are somewhat higher priced than the Sonoran.