The Chic English Basement is an excellent option for small groups visiting D.C.. It boasts both a wide range of amenities and an ideal location, making it difficult to beat—especially for the price. While the Airbnb itself hosts a washer and dryer, modest kitchen, and even a couple "fire" places, its location is a short walking distance from an eclectic commercial area, the National Mall, and the metro.
As for the hosts, Christina and Orestes, they were responsive, helpful, and on their end left nothing to be desired.
I have only one, small gripe about the place, which is that the shower is much smaller than I'm used to. For larger guests this is probably something worth considering, and while the size is certainly manageable, it can feel cramped at times (my party ranged from 6'1" to 6'3" for reference).
Lastly, I thought it worth noting that, though I shared this Airbnb with a couple friends, I can see it being ideal for the average sized family.