[JesseK]

If you can't find a reasonable rate/place in the city, try Maryland or Virginia. Specifically, Arlington, VA is convenient to the city both via highway and metro (Orange Line). Springfield, VA may offer slightly lower rates and the Yellow line will take you directly to the Convention Center, yet I hear that the traffic on 395 is horrific some mornings since 66-E is entirely HOV-2 (so leave early).

As for specific hotels .... well, I live here so I've never actually looked for hotels in the area.