I live in Alexandria, work in DC. With the imminent
decline of WETA, I'm switching to WBJC (91.5 out of
Baltimore). Other posters have mentioned it. It can
be difficult to get the signal to come in, being 50
miles south and all. But I find that if I set up my
FM antenna in the right direction, and switch my FM
receiver from stereo to mono (not all receivers have
that option, unfortunately), I can get a nice clean
signal.

Also, WGMS (103.5) does commercial free music each morning
from 9 till 10:45-ish. It's not much, but it's there.
Dan