What: Senior VP-CMO Where: General Electric Co., Fairfield, Conn. Why: Comstock, who has served as CMO at GE for the past four years, is responsible for all growth and innovation efforts at the company, which include sales, marketing and communications. She oversees GE's “ecomagination” environmental business platform, as well as its “healthymagination” initiative for healthcare. This year, she is leading GE's London 2012 Olympics ad efforts.