5. Eric Schmidt
No. of Entries: 13
With Google's aggressive investment in renewable energy initiatives, Schmidt, who was CEO of the search giant from 2001 to 2011, is listed on 13 entries in the White House visitors log, including a Dec. 3, 2009, Jobs and Economics Growth Forum hosted by President Obama. Brightsource Energy, which counts Google among its investors, has received $1.6 billion in loans guaranteed by the U.S. Department of Energy's Loan Programs Office.