I've been using a Wireworld Aurora 7. 12 ga silver clad OFC. Its flat design makes it pretty flexible. I have it folded back with about an inch radius. For my DACs etc, I agree with @thomaswv that Morrows are extremely flexible at least lower in the line.
Do good power cords have to be stiff?
As far as I am concerned, stiff power cables are a pain in the butt. Wonder if anyone has found a great power cable that is very flexible?