You're thinking of Diet Coke. Aspartame absolutely does have a taste, but it has also been studied an absolutely insane amount over literal decades and nobody can ever actually pin down a negative health effect from it.

This says Coke Zero has aspartame: https://www.coca-colacompany.com/about-us/faq/what-is-aspart...

Coke Zero has aspartame has main sweetener. It also has acesulfame potassium.

Aspartame and/or Asesulfame K make my farts smell like literal death.

You know the kind that's not even funny, the kind that makes you yourself gag from just a little whiff.

Sugar is one of the main contributors to suffering and death in the US. Evidence that aspartame is harmful at all is comparatively weak.

Better the devil you know. Everyone knows that sugar is bad for you. But aspartame is sold as being good for you because it’s zero calories. Must be good, right? It’s Diet Coke! A diabetic friend said his doctor told him regular coke was better for him. It causes migraines (source: me). I have heard many doctors say it is worse than real sugar. Yes, we don’t understand it yet. But we are pretty sure it’s bad, that’s why it’s the devil.