When you get down to it...
This is a useless discussion. This a matter of taste in drinks so there is not really going to be a winner. It's taste in soda for crying out loud.
Anyway I like both and I'll drink whichever one I want when I want it, want to know why? Because it's soda and I have no need for a specific taste
I don't drink sodas for health benefits, I know they both have the capacity to harm me. I continue to drink them based on what tastes better, which is very nearly all Pepsi products. Coca Cola, while a flavorful soda, doesn't have the sweet kick that I expect if I am going to be ingesting that much sugar.
Coke has less high fructose corn syrup. Coke has 39 grams while Pepsi has 41 grams. Diet Pepsi has 69 mg of caffeine, while Coke has 46.5 mg of caffeine. Obviously, with that said, coke is much better. Health-wise. In my opinion at least, Coke is far better than Pepsi.