Best if you're under 30: Merritt Group, New Media Strategies, RedPeg.

Best if you're over 50: Mitretek.

Best if you have small kids: Arnold & Porter, Booz Allen Hamilton, Marriott, Mitretek, and Sunrise Senior Living all have on-site childcare.

Most generous retirement-plan matches: American Physical Therapy Association, LMI, Mitre, Mitretek.

Best free food: CapitalSource provides breakfast and lunch daily.

Best if you want to wear jeans to work: Carfax, CustomInk, EZGSA, FGM.

Best if you want to get out early on Fridays or have the day off in summer: APTA, APCO, Edelman Financial Services, New Media Strategies, Terrapin.

Best if you want Friday off all the time: Center for a New American Dream.

Best gyms: APCO, Choice Hotels, Merritt Group, Sallie Mae.

Best if you want pay that's higher than industry average: APCO, FDIC, Integrity Applications, Edelman, FGM, Great American Restaurants, Weinberg Group.

Best if you want health premiums fully paid: Edelman, EZGSA, Institute for Justice, Merritt Group.

Best if you want your family's health premiums paid, too: Hitt Contracting, Integrity Applications, Wolf Trap.

Most generous vacation time from day one: UCG's take-what-you-need policy.

Most generous tuition reimbursement: FGM, HireStrategy, LMI.

Most generous paid maternity leave: Johns Hopkins Lab, up to 26 weeks.

Most paternity leave at full pay: UCG, eight weeks.

Most eco-friendly offices: APCO, Calvert, Center for a New American Dream.