Just looking for opinions. If the World Championship match between Bobby Fischer and Anatoly Karpov had happened as planned, would Fischer have won? 

Had Fischer been in practice, I think he would have taken Karpov the 1st match. I limit this estimate to chess ability--Fischer's  emotional/pscychological issues could have trumped all predictions.

I agree with goldendog. Based on chess ability alone, I think Fischer would have won the first match. By (let's say) 1978 and onward, it's tough to say. Karpov is one of the best players ever, no doubt.