A portrait George W. Bush painted for late-night host Jay Leno. NBC The most successful people know how important it is to have interests and hobbies outside of their work lives.

Some of these hobbies are useful and considered important networking tools, while others are more focused on personal development and pushing themselves. Some are purely thrill-seeking and allow people in high-stress jobs to forget about their day-to-day responsibilities.

George W. Bush, for example, is an avid painter. The adventurous Richard Branson's favorite sport is kite boarding, and investor Warren Buffett plays online bridge.

Here are the hobbies of 9 highly successful people.