For these lists, we looked at view counts of YouTube's most popular videos this year (in some instances we aggregated views across multiple versions of the same video):
Most Watched YouTube videos (Global):
1. Susan Boyle - Britain's Got Talent (120+ million views)
2. David After Dentist (37+ million views)
3. JK Wedding Entrance Dance (33+ million views)
4. New Moon Movie Trailer (31+ million views)
5. Evian Roller Babies (27+ million views)
Most Watched music videos on YouTube (Global)*:
1. Pitbull "I Know You Want Me" (82+ million views)
2. Miley Cyrus "The Climb" (64+ million views)
3. Miley Cyrus "Party in the U.S.A." (54+ million views)
4. The Lonely Island "I'm On a Boat" (48+ million views)
5. Keri Hilson "Knock You Down" (35+ million views)
Then, to determine the fastest rising search terms for each month, we examined the billions of queries that people searched for on YouTube (through December 15):
Fastest Rising YouTube search terms by month (Global):
January: inauguration
February: christian bale
March: the climb
April: susan boyle
May: pacquiao vs hattonJune: michael jackson thriller
July: michael jackson
August: usain boltSeptember: kanye west
October: paranormal activityNovember: bad romance
December: tiger woods
Fastest Rising YouTube search terms by month (U.S.):
January: obama inauguration
February: on a boat
March: watchmen
April: susan boyle
May: pacquiaoJune: michael jackson thriller
July: wedding
August: send it onSeptember: kanye west
October: paranormal activityNovember: adam lambert
December: tiger woods
There are a lot of interesting nuggets in here. The fastest rising U.S. search term in July was [wedding], clearly related to "JK Wedding Entrance Dance," the third Most Watched YouTube video of the year. And while [michael jackson] was Google's fastest rising search term in 2009, [michael jackson thriller] was the faster rising search on YouTube. Movie trailers ("New Moon," "Watchmen," "Paranormal Activity") and inspirational moments (Susan Boyle, Usain Bolt) were popular, as were sensational celebrity scandals (Christian Bale, Kanye West and, most recently, Tiger Woods).
We hope to expand these lists in the future, so if there are any "Most Watched" categories you'd like to see in 2010, let us know by leaving a comment below.
Jamie Davidson, Associate Product Manager, recently watched "Top 10 quirky science tricks for Christmas parties."
*Note: Some music videos may be unavailable in your country due to copyright restrictions.