In the past 50 years, there have been a lot of memorable TV moments -- the Oscars, Hurricane Katrina, Snooki getting punched in the face -- but after the results of a new survey were tallied, there was one moment shared by US viewers that ranked above all others.

Sony Electronics and the Nielsen TV research company asked about 1,000 Americans to rank TV moments for their impact. Those moments were then ranked by the number of people who said they recalled where they were and who they were with when they saw them happening, as well as whether they talked to others about what they'd seen. We know -- it's kind of confusing.

Taking all that into consideration, the September 11th terrorist attacks were found to be twice as impactful as the televised event that ranked second -- the 2005 coverage of Hurricane Katrina. Rounding out the top five were the 1995 verdict in O.J. Simpson's murder trial, the Challenger space shuttle explosion in 1986 and the death of Osama bin Laden last year.

Brian Siegel, vice president of television business for Sony, said he was a bit surprised by the results, adding he thought entertainment events like the series finale of 'M*A*S*H' (which came in at No. 42), the Beatles' first appearance on 'The Ed Sullivan Show' (No. 43) and the "Who shot J.R.?" cliffhanger of 'Dallas' (No. 44) would rank higher.

While there were some differences in the moments deemed most memorable depending on someone's age and gender, overall, here's the top 20:

1. September 11th tragedy (2001)
2. Hurricane Katrina — the levees break (2005)
3. The OJ Simpson verdict (1995)
4. The Challenger space shuttle disaster (1986)
5. Death of Osama bin Laden (2011)
6. The OJ Simpson white Bronco high-speed chase (1994)
7. The Earthquake in Japan (2011)
8. Columbine school shooting (1999)
9. Oil spill in the Gulf (2010)
10. Princess Diana's funeral (1997)
11. News coverage of the death of Whitney Houston (2012)
12. Capture and execution of Saddam Hussein (2006)
13. Barack Obama acceptance speech (2008)
14. Wedding of Prince William and Kate Middleton (2011)
15. Assassination of JFK (1963)
16. Oklahoma City bombing (1995)
17. Bush/Gore election debacle (2000)
18. Los Angeles riots, Rodney King beating (1992)
19. The Casey Anthony murder trial verdict (2011)
20. The funeral of JFK (1963)

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