Death can do wonders for a star's image, with a survey of online sites showing singer Michael Jackson and actor Patrick Swayze were among the celebrities that generated the most positive comments this year.

U.S.-based marketing firm Zeta Interactive scanned comments on more than 100 million blogs and websites to determine which celebrities received the best, and worst, buzz in 2009 to produce a snapshot of public opinion.

Jackson, who died aged 50 in June from an overdose of powerful medications, was ranked the best buzzed celebrity of 2009, followed by talk show host Oprah Winfrey, teen country music singer Taylor Swift and Swayze.

On the other end of the scale, golfer Tiger Woods' admissions of infidelity garnered him a place on the list of this year's worst buzzed celebrities, although he was third on the positive list before the scandal broke.

Singer Chris Brown, who was convicted of beating his now ex-girlfriend, singer Rihanna, took top prize for the celebrity with the worst buzz.

This year illustrates the true power that social media holds over the fate of a celebrity's brand image, and both the Tiger Woods story and the death of Michael Jackson are evidence of this, Al Diguido, CEO of Zeta Interactive, said in a statement.

With Tiger Woods' catastrophic fall from grace, we saw his reputation drop from 91 percent positive - higher than any other athlete in the world at that time - to only 47 percent positive in a two week span, he added.

On the other hand, after the outpouring of emotion that followed Michael Jackson's death, we saw a celebrity - once recognized for all the wrong reasons - turn into an online sensation with more positive buzz than any other this past year.

Here is a list of the top 10 best, and worst, buzzed celebrities according to Zeta Interactive (http://www.zetainteractive.com):

Best Buzz:

1. Michael Jackson

2. Oprah Winfrey

3. Taylor Swift

4. Patrick Swayze

5. Beyonce

6. Angelina Jolie

7. Jay Z

8. Robert Pattinson

9. Brad Pitt

10. Simon Cowell

Worst Buzz:

1. Chris Brown

2. Jon and Kate Gosselin

3. Kanye West

4. Lindsay Lohan

5. Amy Winehouse

6. Rachel Uchitel

7. Miley Cyrus

8. Paris Hilton

9. Tiger Woods

10. Adam Lambert

(Writing by Miral Fahmy; Editing by David Fox)

Brad Pitt Tiger Woods Oprah winfrey