I would assume those that say there is no difference between the taste of Coke and taste of Pepsi are smokers.
There is a definitive taste difference between the two. They are of very distinctive tastes, or your taste buds are retarded, in which case I weep for thee for thou is surely missing out on the subtle tastes in life.
As a youth my preferred Cola was Coke, but in recent 2 or 3 years has shifted to Pepsi. They've made subtle changes to Pepsi the past decade but its been for the better. But my definitive fave is and always will be Dr. Pepper.
I'm actually surprised DP isn't on the list as in the world of soft drinks, it is a 3-giant standoff between Coke, Pepsi, and Dr. Pepper.