Arguably it is ESPN, which is now valued at about $40 billion:
The reality is that there is not another media property in the world worth as much as ESPN because no media asset delivering content generates close to as much money. Wunderlich pegs the value of the Disney Channel, which is one of the most valuable channels and has the third highest affiliate fees, at $10 billion. It is even uglier in print. The current market value of the New York Times is $1.3 billion. The only media companies in the world worth more than $40 billion are News Corp. ($58 billion) and Comcast ($96 billion). The value of News Corp. is spread out among dozens of media assets, while Comcast derives most of its value from being a cable provider.