Pittsfield is the largest city and the county seat of Berkshire County, Massachusetts, United States. It is the principal city of the Pittsfield, Massachusetts Metropolitan Statistical Area which encompasses all of Berkshire County. The population was 44,737 at the 2010 census. Although the population has declined in recent decades, Pittsfield remains the fourth largest municipality in western Massachusetts, behind only Springfield, Holyoke, and Chicopee.In 2005, Farmers Insurance ranked Pittsfield 20th in the United States as "Most Secure Place To Live" among small towns with fewer than 150,000 residents. In 2006, Forbes ranked Pittsfield as number 61 in its list of Best Small Places for Business. In 2008, Country Home magazine ranked Pittsfield as #24 in a listing of "green cities" east of the Mississippi. In 2009, the City of Pittsfield was chosen to receive a 2009 Commonwealth Award, Massachusetts' highest award in the arts, humanities, and sciences.