Google is not my friend! You’d think this would be an easy list to find…Wikipedia’s article on this very subject, strangely, goes right from stating that Superbowls account for the 21 most watched U.S. broadcasts, to then just listing the top 174 most watched different series finales, followed by listing the most popular series by year, etc.
But, what I am looking for is one long (top 100 or preferably more) list, of the most watched U.S. Broadcasts, by number of viewers, in order- be they Superbowl, Series Finale, Series season finale, OJ’s van chase- whatever. No category breakdowns, special qualifiers, lists that only include series finales of just the one most watched episode from a given series.
1 MAS*H Special CBS 60.2 77 50,150 Feb. 28, 1983
2 Dallas CBS 53.3 76 41,470 Nov. 21, 1980
3 Roots Pt. VIII ABC 51.1 71 36,380 Jan. 30, 1977
4 Super Bowl XVI Game CBS 49.1 73 40,020 Jan. 24, 1982
5 Super Bowl XVII Game NBC 48.6 69 40,480 Jan 30, 1983
6 XVII Winter Olympics - Wed-2 CBS 48.5 64 45,690 Feb. 23, 1994
7 Super Bowl XX Game NBC 48.3 70 41,490 Jan. 26, 1986
8 Gone With The Wind-Pt.1 (Big Event-Pt 1) NBC 47.7 65 33,960 Nov. 7, 1976
9 Gone With The Wind-Pt.2 (NBC Mon.Mov.) NBC 47.4 64 33,750 Nov. 8, 1976
The list is of the highest rated individual shows, but it does also show total households, so you can sort the list to rank by viewership. Early on, Neilsen did not track total viewers.
Remember that most of these shows were in a time when most of us could only watch ABC, CBS or NBC (and maybe a public broadcasting or an independent station).
And during a major event like 9/11 or the Gulf War, the total viewership of the same event might be more, but we’re not all watching the same channel.
The OP mentioned “OJ’s van chase” so presumably was not excluding news events. So I’ll bet that the viewership of the moon landing exceeded many of the events mentioned.