This one is a tosser. Some sources say it is tea, some say it is the soft drink in general, some say it is coffee and a recent survey even says that beer is the most popular beverage in the world. Now how would you measure a beverage popularity (by how many drink it or by how often they drink it, etc) and over what period of time? Because of these issues the title for the most popular beverage in the world can change as frequent as on a daily basis. If we substitute the period of time as being an indefinite amount of time in the past then the title goes to water. Water will 100% come up as the most popular beverage in the world. On the second place it would be tea and then perhaps coffee falling on the third place.