All the posts were good posts and the DC area probably has the most number of Marriott hotels as it is their Corp office city.

To get a fair assessment, one would have to stay in DC many time and "try" out all of the properties. Also, depending on when you go (season) will depend on which property has the best rates.

JW on Penn is a great hotel but sometimes the rates are $499/night. Also they always give full buffet for P and G members and it is an expanded buffet as well!

Try staying by the Metro Zoo on the Red Line. Much cheaper and really nice there. I had anice suite next to the Con Lounge. Also it is right next to the Zoo on the Red Line.

A car in DC?? Only if you know where you are going and have a GPS and don't mind paying for parking. My choice is the Metro and taxis for sure.

Enjoy -- DC is my fav city -- so is Boston!