As you can see #16 as listed is in the ballpark and actually it says in your list's lead paragraph that #16, which is what prompted your list article, was for $45.2 billion. (So, less than this deal.) They get their ultimate figure by adding debt the acquirer takes on (as is typical). Including debt, our article actually says "Including the assumption of DirecTV’s debt, the deal is worth about $67.1 billion" so just a hair shy of #16 on your list if you include the debt.
Either way, this is an absolutely mind-blowing deal in nominal terms. (As are all sixteen on your list.) This is a huge amount of money by any standard on Earth.
What's the last company that got bought for even $30 billion!
This is a mind-boggling sum of money.
Check out the largest mergers and acquisitions of all time:
http://www.bloomberg.com/visual-data/best-and-worst/largest-...
(Do bear in mind inflation - add 45% since 1998 according to http://www.usinflationcalculator.com/)
This deal must still be way up there. I wonder if someone can find the largest acquisitions of the past 2-3 years.