I think i definitely hear a difference between the high end cables and the normal to cheap variety. The better ones improve the tone. Or am i kidding myself?
Well, what difference do you hear?
If it's a cheap cable and it had high capacitance (which can wreak havoc when in series with the pickups), then you would probably hear an audible difference. The distributed capacitance of the cable creates a low-pass filter with the inductance in the pickup.
Any claims about certain shapes or materials letting "more of your tone come through" are misstatements and should be treated suspiciously.
Just find a good shielded single conductor cable with quality connectors and you'll be in good business. There have been plenty of good suggestions here. Brands like Canare, Mogami, and Neutrik are well known and respected because they are quality parts, not because they use secret ingredients.
