TV's most memorable moments

8. The Beatles perform on the CBS “Ed Sullivan Show” in Manhattan. An estimated 73 million Americans tuned in, the largest ever for a TV show at the time, and viewers ranked the appearance as the 43rd more memorable TV moment. (Feb. 9, 1964)

7. The finale of M*A*SH “Goodbye, Farewell and Amen” garnered 125 million viewers in 1983, but viewers today ranked it 42nd in most memorable TV moments in a July 2012 Sony-Nielsen survey. (Feb. 28, 1983)

6. The 1997 funeral of Princess Diana ranked as the fourth most memorable even for women in a July 2012 Sony-Nielsen survey. Princess Diana married Britain's Prince Charles in 1985.

5. Viewers ranked the killing of Osama bin Laden in their top TV moments in a July 2012 Sony-Nielsen survey. President Obama announced bin Laden's death in a special address on the late Sunday evening of May 1, 2011.

4. Viewers ranked the 1995 O.J. Simpson murder trial in the top five TV moments in a July 2012 Sony-Nielsen survey. O.J. Simpson was found not guilty of murdering his ex-wife Nicole Brown Simpson and her friend Ron Goldman on Oct. 3, 1995.

3. Viewers ranked the 1986 explosion of the Space Shuttle Challenger in the top five TV moments in the Sony-Nielsen survey. The space shuttle exploded shortly after lifting off from the Kennedy Space Center in Cape Canaveral, Fla. (Jan. 28, 1986)

2. The only moment that came close to the Sept. 11 attacks in TV viewers' memories was President John F. Kennedy's assassination and its aftermath in 1963. However, that was only for the people aged 55 and over who experienced the events as they happened instead of replayed as an historical artifact. This Nov. 22, 1963 photo shows JFK riding in motorcade with first lady Jacqueline Kennedy before he was shot in Dallas, Texas.

1. The Sept. 11, 2001 terrorist attacks is by far the most memorable moment shared by television viewers during the past 50 years, according to a July 2012 Sony-Nielsen survey. (Sept. 11, 2001)