Entrepreneur: Andrew Mason, 30

Funding: $1.1 billion

Since founding Groupon in 2008, Andrew Mason has made it the largest coupon site. Having spurned a $6 billion buyout offer from Google (GOOG) last year, Chicago-based Groupon raised almost $1 billion of funding in January. The company, which employs 7,000 employees, may generate as much as $4 billion in revenue this year and is weighing a public offering that could set its value as high as $25 billion.

Wisest funding decision: Mason joked about the more than $1 billion that Groupon has raised: "Deciding to completely bootstrap Groupon and never taking any money from investors."