I've been yapping about those cables a little, went through this quite a bit lately. By far the best speaker cable for the price I've found was Tara Labs Prism Klara. It used to be around $.79/ft, then went to $1.00/ft. And just as I was ready to put it everywhere... Tara discontinued it, of course.
They replaced it with "the same thing, only improved" according to them. It ain't. The new version is called Prism Klara PS -- they raised the price to $1.50/ft, it uses a different jacket, wider spacing between conductors, and who knows what else. Doesn't sound anywhere near as good as the original, it's a much darker, flatter sound, with more bass and less treble, and much less open midrange.
It still is pretty good overall, considering the price. And is far better than the old "power cord" (yes I've tried lots of it) or lamp cord. The Monster I've used is just junk compared to anything else, even the zip cord. An edgy quality, with sharp transients and difficult mids. Although of course there are a lot of different versions of MC and I haven't used them all. I'm sure Kimber has some decent ones, they've been doing this for a while, but I haven't used any.
The best audiophile cable I've used, not too exotic ($180 for 2 meter pair) is Kubala-Sosna. This is the cheapest they make, goes way up in price from there. It is just outstanding sound quality, check around some of the audio forums for some positive feedback. But while I liked it in listening systems, overall I felt it was a little too "lively" for my mixing needs. I like it when I want some impact and tremendous clarity, but somehow it's not as "neutral" as the original Klara, so for monitoring and mixing I went back to that.
IMO all cables are just equalizers. They will work differently in every system, depending on mic, preamp, mixer, converter, amp, speaker, whatever. So I just use what sounds right to me, with a given set of equipment.
Steve