Well, Diet Coke to Diet Pepsi. And not because of the taste. Because at the supermarkets in my area, I have a choice between 2 liter Diet Pepsi's for $1.59 or 1.5 liter Diet Coke for $1.39. Every time I bought one, I felt like I was ripping myself off. Of course, even better is Dr. Brown's 2 liter for 99 cents.