I prefer McDonald's fries to pretty much every other fry I've ever had, though I will concede you could probably amplify your audience base by doing any of the below:
- Cooking them in lard not oil (they used to be better, though they're still amazing as is)
- Adding different seasoning/topping options, like cajun from Five Guys, or garlic fries, or chili/cheese fries, etc.
- Making a big mac style, which is just a copy of animal style at In-N-Out but they both pretty much originate from the same creative source
- Making different cut options, like krinkle, thick, ultra-thin etc.
Even with all the above given potential options, having eaten my fat american share of all of the above from a variety of places, McDonald's fries are still king--frozen and all. In fact I am not remotely convinced giving me fresh potato cut fries would improve it in anyway, see: In-N-Out fries alt: garbage
Also, point of fact, if you're 'doing it right' as a McDonald's employee, the rule is to throw out cooked fries that have been sitting uneaten for more than 7 minutes, though its probably true that isn't followed 100% of the time.