I think that McDonald's french fries are good but I prefer Arby's french fries. Where I live Arby's french fries are always hot and fresh. So far I have never got any bad fries from them.
I'm not one for eating fast food, I could count the number of times I've eaten at fast food restaurants in the past ten-years on one hand. However, I had Burger King fries a few months ago and they were horrible. Dry, cardboard like fries and the portions really are pathetic. Large is a small by any standards.
The fact that I have an opinion on this shows my efforts to cut fast food out of my life haven't been very effective so far. I think Mcdonalds has the best fries but Checkers is a close second. I guess it matters to say I've never actually had bad fries at a fast food place just some better than others.
For just regular fast food string fries, my favorite would have to be McDonalds fries. My all time favorite fries are from Chick-Fil-A. I like to get Chick-Fil-A fries and ask them for either a honey mustard or polynesian dipping sauce and dip my fries in them.