Ginni Rometty

In her second year as CEO, Rometty is sinking IBM's resources into commercializing Watson, the Jeopardy-playing supercomputer. Rometty believes that Watson, a machine that can not only crunch numbers but also learn things, represents new sales opportunities for Big Blue. She's also pushing into underserved markets -- Africa, for example -- and picking up new customers in marketing and finance, to keep the 102-year-old tech company ahead of the competition.