A few years ago, while visiting my son and his family in Mexico, he pointed out to me that the Coke there in bottles used sugar and not corn syrup, which was the only reason he bought the bottles. I subsequently saw bottles of Coke imported from Mexico in a supermarket near me in the Dallas area that has a large Hispanic customer base and when I checked the label I saw that corn syrup was used. So, it looks like you still have to check the labels for the Coke in bottles. Maybe even in Mexico.
lilbuddypizza is correct about high fructose corn syrup. In most cases where it is used it is because it is the cheapest form of sugar, not the best. It's use is pervasive, in just about every food product where sweetness is desired.