31. Carol Meyrowitz
Days before Meyrowitz became CEO of the nation's largest off-price retailer in January, TJX revealed a massive customer data breach. It was a tough way for the company vet to begin her tenure. The $18 billion retailer, whose U.S. stores include T.J. Maxx and Marshalls, faces lawsuits from consumers, banks, and investors; related charges have eaten into quarterly profits. On a positive note, sales have been strong, up 7% in the first half of this year.