When I was in the market for a good quality, neutral (meaning, it will NOT colour your sound by cutting down the high frequencies etc.) and silent instrument cable for my guitars and basses, I stumbled on the 4.5m Sommer The Spirit XXL and I've been using one since.
For people that need a cable of this quality but a little bit longer, the 6m would be perfect.
Oh, by the way, they DO get tangled but I've never used a straight cable that doesn't do that (if that's your top priority and you are willing to sacrifice sound nautrality, EMI etc, feel free to opt for long coiled cables).