I have scrolled down and looked through the suggestions for Thanksgiving i DC, however, while they all seem to be outstanding resturants they tend not to be what I associate with a "chowhound" meal.
Being a first time visitor to the US during thanksgiving, I would be happy to enjoy any hearty, less upmarket, relaxed thanksgiving dinner or buffet. Any suggestions in this respect would be greatly appreciated!
As far as more top of the line eating goes, my experience (from Europe) is that you should avoid those venues on major holidays and festivities; even a weekdays are better than a Saturday.
all the best