Number of households: 11,807
Change YOY: 1.37 percent
Change since 2000: 14.75 percent
Average household income: $111,520

Why: Batavia, located near the Fermi National Accelerator Laboratory (above) and home to the U.S. Energy Dept.'s research arm for high energy physics, experienced the fastest growth in Illinois and is expected to continue expanding. The city anticipates that Batavia's population will reach 30,640 by 2015, up from 27,154 in 2009, according to U.S. Census Bureau estimates. Major employers include Universities Research Assn., garden and yard accessory manufacturer Suncast, and the city.