Question:
What's the difference between "OFC" speaker wire, and normal speaker wire?
Answer:
OFC means oxygen-free copper. I agree with the above answer--it's all marketing hype. The most important quality you should look for is wire size as indicated by the guage (AWG). Lower AWG numbers are better, and it doesn't matter what kind of wire you use. Lamp cord is fine. The advantage of speaker wire over lamp cord is that the speaker wire is marked so you can identify which lead is which. This way you can make sure you connect the "+" or red terminal of the amp to the "+" or red terminal of the speaker.
A good wire size is AWG 14 unless you have very big speaker a long distance (20') from the amp, then go to AWG 12 or 10.