I have a preference for Aspartame. Unlike Diet Coke, Pepsi changed Pepsi One from Aspartame to Splendra without retaining the old formula in a different product unless you count Diet Pepsi which I don't. I went around to all the stores in town and bought all the silver cans of Pepsi One. Here and there I find an old can or bottle of Pepsi One in some small convenience store while travelling but otherwise I have switched to Diet Coke.