Great question that is highly subjective. One important factor will be your commute, as traffic and getting around the DC area is notoriously difficult. Will you be able to get to work via public transportation (and there certainly is a premium for being walking distance to a Metro rail station), or will you have to take a car, and therefore need parking at home.
Other considerations would be your budget, personal safety threshold, whether or not you have pets, and what you like to do in your free time.
The close in suburb of Takoma Park, Maryland offers a host of transportation options, a great little downtown for shopping, a kinda funky vibe, with a range of housing options, all in a fairly verdant setting.
If you would liek to share some more details, be happy to make some other suggestions!