McDonalds
Small fries costs £0.89, weighs 80g. Cost per gram = 1.1125p
Medium fries costs £0.99, weighs 114g. Cost per gram = 0.8684p
Large fries costs £1.39, weighs 160g. Cost per gram = 0.86875p
The trend in McDonalds is, the more you buy the better the value. But for fries, the value decreases when upgrading from a medium to a large. Madness....
*weights are according to the official McDonalds Quality Reference Guide.