Hi,
The best cable in the world would be no cable. The next best cable would be the cable with the lowest resistance/capacitance. If you're looking for a cable to create a sound signature or EQ your system then you're not looking at cables properly in my opinion. You want the cable to completely disappear if possible, although this is not possible LOL but you do want the cable to have a very low overall effect on your system. You don't just want to hear just the guitar strings, you also want to hear the wood on the acoustic guitar. Less is more in this situation.
This is just my opinion but I have had over 500 different cable models. Have a great Sunday.
Cheers Bob