XOM

Exxon Mobil Corp.

One of the world's largest energy companies, ExxonMobil finds, refines, and sells crude oil and natural gas, plus petrochemicals, lubricants, and gasoline sold at its familiar gas stations. Its roots trace to John D. Rockefeller's Standard Oil, which the U.S. Supreme Court broke up in 1911; two of the pieces—Standard Oil of New Jersey and Standard Oil of New York—reunited when Exxon and Mobil merged in 1999. Fun fact: the "Exxon" name was one of about 80,000 computer-generated candidates picked in 1972 to replace the old "Esso" brand.