I prefer Pepsi and here are the reasons
Pepsi is sweeter than Coke, so right away it had a big advantage in a sip test. Pepsi is also characterized by a citrusy flavor burst, unlike the more raisiny-vanilla taste of Coke.
Turning to nutritional content, Pepsi has slightly more sugar, calories, and caffeine. Coke has slightly more sodium.
But coke is winning the cola war cause of the branding