Stayed at the Fairfield Inn & Suites Dulles Airport Chantilly, 3960 Corsair Court, Chantilly, Virginia 20151 with my family of five and two dogs.
Very accommodating -- we asked to be on the end of the hotel, on the 3rd floor, away from the airport (to avoid airplane noise and insure that the dogs wouldn't bother other patrons). They made it easy.
The price is less than other hotels in the area.
The hotel looks new and is very clean.
The breakfast bar is well stocked, clean, and attended.
The staff is polite and professional.
Not a great location as far as restaurants, the metro, or easy access to DC but that's not the reason for our stay. It was about $70 / night less expensive than staying closer to DC and it was close to everything we needed (a Super Target, Pender Vet Clinic, the Fair Lakes Mall, the Air and Space Museum at Dulles Air Port, and our family).
We would definitely stay there again.