Manoj Bhargava

India-born Bhargava has had a handful of different careers: demolition man, Princeton undergrad, cab driver, plastics executive. He even spent 12 years living in a Delhi ashram as a monk. But he struck it rich eight years ago with 5-Hour Energy, a two-ounce elixir of caffeine, B-vitamins and taurine that sells for $3 a bottle and has made him a billionaire. 5-Hour's parent company, Living Essentials, nets about $300 million on $600 million annual revenue. Bhargava owns less than 40% of the company, having pledged 45% to philanthropic efforts. He's known to be litigious, so copycat brands beware.