Embassy and Homewood Suites always have self laundry facilities. Some even provide in-room washer and dryer. Same goes for Hilton Vacation Club locations which you can sometimes get for normal hotel prices and many rooms include FREE in-room laundry machines.

I stayed at a Courtyard by Marriott in Marlborough, Mass this weekend which had self-service laundry (coins needed) and provided free supplies (Tide). About $3 wash and dry per load.