pros:
1. public transit. Metro is pretty good, bus is fantastic within the district. A car is a liability in the district. Outside the district ... well why would you want to go there anyway?
2. Diverse neighborhoods. Gentrification has been creeping west to east across the city, but between lily white Georgetown and what remains of "Chocolate City" in Southeast are a number of incredibly diverse communities.
3. I think the food is pretty good. The K St/downtown area it's pretty lousy, but its not hard to get good eats in Georgetown, Adams Morgan, Dupont, U St, and parts of Northeast. If you can find the real thing, the half smokes are damn good.
4. Ambitious people who give a shit about interesting things. Bars are packed with 20 somethings who work for nonprofits saving the gay ostriches of Namibia. Yet almost everyone is cynical enough that they don't actually expect to change the world.
5. Exceptional parks. Decent hiking in Virginia national parks. Not far from decent beaches.
6. Surprisingly good biking despite the dumb fucks on their cell phones. The city is packed with bike messengers who are aggressive and keep the cabbies in line. Traffic is bad enough that cyclists are more worried about hitting a car than vice versa.
7. Not nearly as dangerous as it's made out to be. Crime is for tourists and dealers. Take a stroll through some of the Northeast neighborhoods and you'll get mugged. Live in those neighborhoods and you'll be fine.
cons:
1. The rest of the country sends their most ambitious lawyers to DC. Fortunately, most of them live in NoVa or never leave Capitol Hill so you probably won't have to actually interact with them.
2. Crap tech scene. Mostly gov and large contractor stuff who have piss poor standards.
3. Rent. Although, if you aren't a prick you can find some decent places in the "rougher" parts of Northeast.
4. Southeast is a little bit of Beirut circa 1980. No, you will never have to go there, but knowing that it exists is kind of a constant bummer.
5. Local politics is ridiculous. Marion Barry is a national punchline, and he's definitely not the worst of DC politics. Congressional control + the landlord lobby makes for a giant clusterfuck.
6. The weather is disgusting.