Number of households: 11,743
Change YOY: 0.62 percent
Change since 2000: 5.7 percent
Average household income: $154,343

Why: A wealthy town in Middlesex County, about 14 miles from Boston, Lexington is home to companies in the biotechnology, defense research, and software industries. The unemployment rate in Lexington in March was 4.5 percent, lower than Massachusetts's 8.2 percent, according to the Massachusetts Executive Office of Labor and Workforce Development Division of Unemployment Assistance. Ratings on greatschools.org show that the area's schools perform well above average.