Bill Gates is on top of the world once again. For the 15th year in a row, the Microsoft CEO has been named as the richest man in the US. Gates is estimated to have a net worth of $57 billion USD. In 2007 Gates was valued at $59 Billion. It seems like the millionaire has been affected by the current downfall of the US economy. But, despite that he is still on the very top.

Second on the list is Warren Buffet. Buffet is valued at $50 billion USD.

The Forbes 400 list has also included newcomer Mark Zuckerberg. Twenty four year old Zuckerberg has an estimated net worth of $1.5 Billion. Zuckerberg made his money through his creation of the social network ‘Facebook’.

Talk show giant Oprah Winfrey also made it into the Forbes 400. Winfrey is valued at $2.7 Billion.