Television's most powerful moments

    1 / 20

    Osama bin Laden

    In the first year of the century, Yahoo released the 20 most popular terms for the first time.

    The Yahoo! Buzz Index Top 20 Leaders for 2001:
    1. PlayStation 2
    2. Britney Spears
    3. WWF
    4. Dragon Ball Z
    5. Napster
    6. World Trade Center
    7. Harry Potter and the Sorcerer's Stone
    8. Dale Earnhardt
    9. NASCAR
    10. Internal Revenue Service
    11. Jennifer Lopez
    12. `NSYNC
    13. Las Vegas
    14. Eminem
    15. Osama Bin Laden
    16. Nostradamus
    17. Backstreet Boys
    18. Pamela Anderson
    19. Morpheus
    20. Pokemon
    The number one slot belonged to PlayStation 2, which led to the optimistic prognostication "that gaming culture may be on the verge of eclipsing movies and television in the pop culture lexicon."

    The terrorist attacks on Sept. 11, 2001, pushed the term "world trade center" into No. 6. The mastermind, Osama bin Laden, registered at No. 15, followed by Nostradamus, due to a hoax that the 16th-century so-called prophet predicted the events. Searches at the time also underwent an "upswing in patriotism. Searches on anthems, patriotic speeches and songs, and the American flag (26) soared as Americans looked for ways to express their support for their country."

    According to a new study released by Nielsen, the Sept. 11 terrorist attacks, Hurricane Katrina and the O.J. Simpson verdict were among the most "impactful" moments in television history. Here are some of them.