Look for tinned OFC wire and one that has AWG designations. Tinned copper wire has a tin (or tin/lead alloy) plating the prevent the copper from oxidizing. When copper oxidizes, it's conductive properties diminishes. Also, cheaper cables that are not AWG designated may not be the true size it says it is. Some companies will say their wire is a certain ga, but the actual conductor is much smaller. AWG is the American standard for gauging conductor diameter, not conductor and insulator together like the cheaper companies do. Cheap cables will have a small diameter conductor with a thick jacket to look big. But if you get a AWG 0ga cable, you are actually getting a true 0ga sized conductor.
Rockford and Monster make good cables. They have more strands than most other cables.