Audio cables and adapters form the crucial connections between all of your equipment, and while the standard of most modern leads is actually quite high, there are a few things worth knowing about that will affect how well they carry signal.
In the analogue realm, it's all about resistance and shielding. Thicker, shorter, oxygen-free cables will offer the least resistance. Gold connectors will resist corrosion, while shielding will prevent outside interference.
With digital fidelity isn't an issue, but build quality does matter. A thick, flexible outer layer will add years of life to an adapter that's constantly being plugged, unplugged, and packed away into a bag.