What is the most viwed video on YouTube?

Evolution of Dance, with 124,606,836 views

Edit: This is not true.

Justin Bieber ft. Ludacris - Baby has accumulated more then 771 million views.

Check out the related link - there you'll see the top 10 most viewed videos of YouTube as of right now.

^^That is no longer true either. Currently the most viewed video is PSY - Gangnam Style

Now, the most viewed video on YouTube is Despacito.