I have stayed at the Monaco in D.C. several times. It is centrally located for business or tourism. You couldn't ask for a better location--close to major sites, transportation, and the Mall. Plus, the hotel is quite nice, well decorated and appointed. The staff always aim to please and are super friendly. On one prior visit, I arrived VERY early from a redeye flight and they even let me check in at about 7:00 a.m.
Usually, I would give the hotel five stars (at least for each of my past visits). I am knocking a star off this time only because I had the front desk arrange a cab for me to Reagan National this time (usually under $20). I didn't notice at first because it was early in the morning, but the cabbie didn't run the meter and instead gave me the "pay me what you think it was worth for me to pick you up at 4:00 a.m." shakedown. This was somewhat distasteful, but I'm not sure I can blame the hotel for that (unless the clerk had some sort of "arrangement" with the cab--not sure).