The most watched sporting event in the world is football (European Football). However, the single most watched event in history was the semi final match between India and Pakistan during the cricket world cup in 2011.
To give you an idea of how popular football is, the 2006 world cup final drew 716 million viewers. While the whole tournament attracted 30+ billion non-unique viewers.
As for recurring events, 600 million households watch the English Premier League (football) a week. Bear in mind that 600 million doesn't include illegal viewers.
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Cricket.
beach volleyball
Seinfield.
The show that had the highest ratings in 1992-1993 with 20,388,900 viewers was 60 Minutes.
I believe its Baseball.
MASH and CHEERS
mash
Sport Relief 2006 - 2006 TV is rated/received certificates of: UK:PG
Dick Francis Blood Sport - 1989 TV is rated/received certificates of: UK:PG
college football.
CBS currently has the highest overall TV ratings in the US.
In terms of ratings as of the 2014-2015 tv season, Family Guy is still the highest viewed animated series on American television.