Question: What is the most watched video on youtube of all time?
Disambiguated questions and answers: question: What is the most watched video on youtube of all time as of August 4, 2017?
What is the most watched video on youtube of all time as of July 10, 2017?
What is the most watched video on youtube of all time as of November 24, 2012?
answer: Despacito
See You Again
Gangnam Style
Natural Questions answer: Despacito (from the Wikipedia article "List of most-viewed YouTube videos")