What could possibly beat the biggest broadcast event of every year? I thought it might be the final episode of M*A*S*H, but it wasn't. The "Who Shot JR" reveal on Dallas? Not that either. In fact, it didn't even make the list. 

The answer is One Giant Leap for Mankind. Although I call a slight foul on the linked article. The Super Bowl is on only one network at a time every year. The Apollo 11 moon landing was on every station and its audience was cumulative amongst all the networks covering it. (Although I have no doubt the majority were tuned to Uncle Walter Cronkite on CBS.) 

Besides the lunar landing, the list of the most watched shows in broadcast history includes mostly the Super Bowl. But there's one exception that beats even the M*A*S*H finale. It happened in 1974 and again, was on all the major networks. Try and guess what it was, #11 on the list. Then check here to see if you got it right. Have to admit I never would have guessed it, but it makes perfect sense. 

We can only hope history repeats itself!