Since switching to diet drinks, I have been trying to find Diet Coke with Splenda, but haven't been able to locate it yet. However, I stumbled across Coke Zero and decided to give it a shot.
Like Diet Coke, it also has aspartame, but also adds acesulfame potassium, whatever the hell that is, as a sweetener. I am sure it's good for you.
I have to say that it is much better than Diet Coke - there is hardly any aftertaste at all, and is very close to the taste of a regular Coke, but without the "mouth feel" of the full sugared version. I'll be sticking to this until I can find the Splenda version and do a side-by-side comparison.