Coca-Cola has the superior brand, but I grew up drinking Pepsi for the most part, so that might be a factor. Coke tastes good, but it's not the same, it just doesn't satisfy.
I'm quite sure I'd feel the same way on blind tests and I was assuming that most people have this keen sense when it comes to their favorite drink.
Their apparent superiority is just a product of massive investment in marketing to maintain their status. If it tastes the same as Pepsi or no-name cola, then what else could it be?