1) Michael Bloomberg – Bloomberg  LP and Bloomberg Media
2) Rupert Murdoch – News Corp
3) Donald and Samuel “Si” Newhouse - Advance Publications
4) Cox Family – Atlanta Journal-Constitution
5) Jeff Bezos – The Washington Post
6) John Henry – The Boston Globe
7) Sheldon Adelson – The Las Vegas Review-Journal
8) Joe Mansueto – Inc. and Fast Company magazines
9) Mortimer Zuckerman – US News & World Report, New York Daily News
10) Barbey family - Village Voice
11) Stanley Hubbard – Hubbard Broadcasting
12)Patrick Soon-Shiong – Tribune Publishing Co.
13) Carlos Slim Helu – The New York Times
14) Warren Buffett – regional daily papers

WORTH MENTIONING

George Soros
He doesn't own any media outlets, but he's managed to insinuate himself and his money into the media culture, making connections with the nation's top publishing organizations. 

Soros (a liberal) has direct ties to more than 30 mainstream news outlets - including The New York Times, Washington Post, the Associated Press, CNN and ABC. 

The Koch Brothers
Charles and David Koch don't own any media outlets but have effectively co-opted conservative media outlets like Fox News.
Their political contributions began to attract widespread attention from media outlets in 2008.

They, and their political allies, have been described as a rival to the "establishment" wing within the Republican Party, and have expressed frustration with establishment candidates running in the 2016 Presidential election.

Time for me to walk on down the road...