The original Coke Zero was absolute perfection in a can. Sometime in the 2010s they rebranded to Coke Zero Sugar, which was sweeter and less "sharp" tasting than Coke Zero.

I feel like they have shifted back to the original a bit, but I'm not sure if it's gotten better, or if I've just gotten used to it. But yeah, that OG Coke Zero with the sweetness dialed back was super refreshing when ice cold.