When in the DC area I’ve always tuned to WHFS, and the KP Spouse credits WHFS with contributing to the development of his taste in music that kept us up talking until 2AM on our first date (and many times since!). Although it had gotten to be a shadow of its former self in the past five or so years.
If you miss it, try WOXY, which used to be the radio station in my college town and has now gone entirely online. Always independent, never commercial, and to this day continues to be a great listen. As a matter of fact, one of the things I like best about the combination of the wireless network in the house and the little JBL donut speaker I bought for my iPod is that through my laptop I can listen to WOXY while I’m cooking.
Here’s the playlist. Give it a listen!