I recommend the Outwin Boochever Portrait Competition now up through Feb 23, 2014 at the National Portrait Gallery. Some beautiful work...and it's right next to the America's Presidents Gallery...because those post-Civil War presidents had great facial hair.
Added bonus: The National Portrait Gallery is open until 7pm daily, is a stones throw away from Proof, Zaytinya, Jaleo, Rasika, and Poste (just to name 5 places to go eat afterwards), and Metro convenient.
Really it's a no-brainer.