What is the most popular drink in Italy?

Can you tell me, what is the most popular beverage consumed in Italy? Is it a traditional Italian espresso, perhaps a glass of crisp prosecco, or maybe something more unique and lesser known? I'm curious to know what the locals tend to gravitate towards when it comes to quenching their thirst. Could you elaborate on the popularity of this drink and perhaps share some insights into its cultural significance or historical background?