Most of the Chinese restaurants along H in Chinatown are passably mediocre. Full Kee, Eat First, Chinatown Express, Tai Shan, and Ming's were all OK the last time my parents* were in town for a while (a few weeks ago). The bakery on 6th is also OK, and does a serviceable Hong Kong-style breakfast/lunch. The only standout Chinese food experience is China Boy Noodles, also on 6th; it's a rice noodle factory with one table and an un-exotic menu. (Freshness really matters with rice noodles.)

Honestly, Daikaya and Rasika are the best Asian restaurants in/near Chinatown, but they're Japanese and Indian, respectively.

* My mom ran Chinese restaurants, and a great-uncle owned a Chinese restaurant on H in the 1960s. His family now lives in Maryland, of course.