Which person made the most money in 2008?

Which person made the most money in 2008?
Opinions seem to vary. It depends on how they measure it.

Parade magazine ranked Jay-Z as the top money maker in 2008. (source: http://www.southernstylemagazine.net/Previous_8.html)

Madonna was the top money-making person in "music". (source: http://www.billboard.com/bbcom/news/madonna-tops-2009-music-money-makers-list-1003940730.story)

Will Smith is the top money-making "star" of 2008. (source: http://www.cnbc.com/id/28508603/?slide=11)

The richest person on earth in 2008 was Warren Buffet (worth an estimated $62 billion). (source: http://top--10.blogspot.com/2008/03/top-10-richest-person-in-world-2008.html)