Tom Cashel said:
Yes, by all means...ignore the fine, clean, well-maintained, relaible mass-transit system known as the Metro, and contribute to the catastrophic, apocalyptic traffic snarls that plague our fair city and its environs. Get a car! And get some high-blood-pressure medication to go along with it, because you will need it.
Metro's not ALL that; it's very good, but you'll want to make friends with someone who has a car and will drive you places. Let them deal with the agonizing insurance rates and the traffic that makes you want to toss a Crushing Fist of Spite every five minutes. Out of the eight people in my gaming group, five have cars; only two drive to work.
If you want to, you can, in fact, live fairly easily without a car, as I do. I live close to the Clarendon* Metro stop, and commute out to Shady Grove Metro. My grocery and CVS are within walking distance, as is a mall (Well, I've walked to Ballston before on nice days) and a movie theater (Courthouse). Heck, I can even walk to Dream Wizards from the Metro (uphill...both ways!) or, if I'm feeling really self-flagellating, the Compleat Strategist out in Falls Church.
* - Man, I miss Fantasy Forum.
Let's see...taxes are lower in Virginia than Maryland, where they're lower than in DC. The roads are, as others have mentioned, amazingly annoying. Nightlife is fairly subdued, compared to, say, New York, but almost anything's there that you might want to do. We might even have a baseball team, hopefully in DC rather than Arlington. People've told you everything's expensive, which is true. For a while, finding an apartment was nearly impossible, which will be harder near the Metro; that's eased off lately, but it's still a pain in the rear end.
You also get the joyous feeling of, when reading a book or seeing a movie, going "Hey, I've been there!" It's actually tremendously cool, really. Stuff Happens Here, which is not always good.
Brad