Nice question. I'll try Inferno Pizza in Darnestown.

I mean New York is New York. Pretty much infinite things to see and do, and I feel like every east-coaster should have at least one New York experience under their belt. It can be an overwhelming place to be for sure, but I usually have a great time. It's expensive though (though admittedly not much worse than just day-to-day-life in DC).

I find Chicago a similarly good time as New York, but I would recommend waiting for the warmer months on that one unless you know what you're getting in to. While the temperatures are currently alright, it can be brutally cold at times.

I also really like Philly and it's cheaper and quicker to get to and do stuff in.

Still haven't had a chance to get up to Boston myself.

Not a lawyer, and never done this, but the law is pretty clear about security deposits and I'd imagine you could probably easily pursue a case in small claims at this point. Small claims cases are relatively informal and you do not generally need legal representation. You may also be referred to a small claims mediator prior to trial that may negate the need to have an actual trial too. Here's the DC Court's page about the process and how to file a case.

One final thing you may want to do if you think small claims is the route you want to take, is send your landlord a certified letter telling them they have 7 days from receipt to send return your deposit or that you will be filling in small claims. I only suggest this as threat of legal action can light a fire under people's asses and could avoid the rigamarole of small claims, but this isn't totally necessary either. If you do decide to do this and they don't respond to that letter, well you sent it certified and now have additional evidence that they knew they were illegally withholding your deposit.