Make it three. What the cable companies and some purists will have you believe is that "better" cables will give you a lower Bit Error Rate (BER). It's true that even digital signals can be corrupted by noise and as the BER goes up your Signal to Noise Ratio (SNR) goes down. However for short runs at moderate data rates (like USB 2.0) this typically isn't a problem.

If you have some extra money sitting around you can purchase a USB Bit Error Rate Tester (BERT) for around $1000 and test your cables yourself. I wouldn't recomend it though, there's plenty of other cool things you could spend that money on.