Good-quality generic cable is fine--just make sure it's thick enough to keep cable resistance to 0.3 ohm or less. You can do that by selecting 14-gauge or 12-gauge cable. (As the gauge number becomes smaller, the cable is thicker.) For example, 22-gauge cable is like telephone wire--very thin. For short runs of cable, 6 to 8 feet or so, you can get away with 16-gauge cable.
Others on the boards here will tell you where you can buy inexpensive cable--AR, Recoton, Radio Shack, etc. If you want to use branded cable like Monster, it's okay. The cable is fine but you'll simply pay more for the same copper.
Axiom Resident Expert