Michael O'Brien: City Manager, City of Worcester (Until Jan. 5, 2014)

O’Brien may use tortured syntax when he speaks in public. But his recent announcement that he will leave his post next month to become vice president of The Winn Cos., a real estate developer, was crystal clear, sending tsunami-like political waves throughout City Hall and the rest of Worcester. He is the city’s most powerful and influential city manager since the late Francis McGrath, and his absence will be felt.

As the city’s “CEO” since 2004, O’Brien has been quite adept at holding on to his job by keeping at least six of the 11 city councilors — his bosses — happy. And like McGrath, who ran City Hall for more than three decades until the mid-1980s, O’Brien has managed to keep far more than a simple majority on his side by his tireless, professional, disciplined and charismatic leadership. His power and influence have stemmed from competence rather than corruption. In Worcester, that goes a long way.

As even O’Brien’s harshest critics would begrudgingly agree, Winn’s gain is Worcester’s loss. Yet, as a major executive at Winn, we can only expect to see more development projects from the firm in New England’s second-largest city in the years to come.

William Manley: Founder and CEO, Calare Properties, Hudson

Warner Fletcher: Partner, Fletcher Tilton, Worcester

P. Kevin Condron: Chairman and CEO, The Granite Group LLC, Concord, N.H.

Ralph Crowley Jr.: CEO, Polar Beverages, Worcester

Clifford J. Schorer III: Board of Directors, Worcester Art Museum

Joseph Salois: CEO, Atlas Distributing Inc., Auburn

John Prosser: Chairman, Seven Hills Foundation, Worcester

James Paulhus: President and CEO, UniBank for Savings, Whitinsville

Jim McGovern: U.S. Rep., Worcester

Charles Monahan: President, MCPHS University, Worcester

David ‘Duddie’ Massad: Chairman, Commerce Bank & Trust, Worcester

Gordon Lankton: Founder, Museum of Russian Icons and Gallery of African Art, Clinton