14th & K
Ceiba is also pretty close and has latin fusion. I like their lunch steak with chimchurri sauce. Corduroy is also not too far of a walk if you are a walker and very good contemporary american cuisine. You are also pretty close to Chinatown and Penn Quarter for some more options: Proof, Zola, PS7, Zengo, Matchbox, Zaytinya, Jaleo, etc.
two new places just opened right by here that have both been well-received.
the first is Siroc and i haven't heard one bad thing about it. definitely look it up, everyone is just raving about it.
the second is potenza, a new italian place. i haven't heard quite as much about it, but it also has gotten good reviews. but perhaps not the glowing praise that siroc gets.
the next morning before you leave please stop by juice joint for a really good on-the-go breakfast and what's perhaps the best smoothie you'll ever have in your life.
brasserie beck is definitely a consistently good, solid bet.
Brasserie Beck is at 11th and K and has a wonderful Belgium menu. The mussells and frites are the best in town (in my opinion). Other dishes I love include the onion soup and the rabbit. The food tends to be on the heavier side but it's really, really good. They also have one of the best beer lists in town.