Whoa, Bruce: talk about opening up Pandora's connector box. Let me just preface what follows by saying this is not a rant :-) ; I've been in radio/TV/recording for... well, a while now. I only point this out because it's given me many years to use many different types of cables, for a variety of A/V uses.
1. The quality of the cable in the box depends on the company; for example, RCA provides some of the best cables with their DVDs that I've ever seen in a box; on the other hand, most basic cables are just fine, and you won't notice any difference in quality unless one of two things is going on: either you have some sophisticated testing equipment, or you're so far gone that you can't really tell the difference any more between Bryers vanilla and Ben & Jerry's vanilla.
There is one caveat: the weaker the shielding, and the more angular bends it carries, the higher the likelihood of interference, which can cause both audible and visual noise. And poorly attached, poorly made connectors do the same thing.
2. Zip cord, or that 14, 16, and 18 gauge stuff you get at the hardware store for wiring lamps, works pretty darn good for speakers. Always has, always will. And, if you go into a recording studio that's been around for a few years, you'll still see bits and pieces of Radio Shack RCA cables mixed in with the fat stuff used for patching various pieces of hardware.
3. I've never had, nor wanted, the opportunity to compare the really expensive brands side by side, but after listening more than just a bit, trying to tell the difference between Monster and WalMart is like trying to perceive the "robotic" sound of a DVD because it is digitally recorded... .
4. There's a professional installer, goes by the name of randy (that's right, with a lower-case "r") who hangs out here from time to time who HAS had a chance to compare the high-priced brands, and he'll tell you that he's only ever heard a difference in one single brand, and that even though he believes it's there, he won't recommend that anyone should actually spend that kind of money unless they have nothing else to do with it.
That all being said, and this not being a rant, let me wrap up by saying that of course, its totally subjective, and laying some nice, smooth, fat cable with fancy connectors gives me a really good feeling... but that's all it gives me.