Very Dirty, Very Disappointing
I used Tripadvisor to review various properties at the Philadelphia airport before booking and the Fairfield Inn was highly rated so we booked. We were astonished to find that the reviews in no way reflect reality. 
I want to say first of all that the staff were professional, competent and extremely helpful, so this review in no way reflects on them. While the lobby and breakfast room were clean in appearance, the room was a completely different matter. It was shabby and filthy. The sheets and towels were clean but the furniture was sticky, the shower curtain had mold around the edges, and the chair in the room had multiple stains on the seat. The curtains and dust ruffles around the beds were very wrinkled and appeared to have been crumpled in a ball before being used. After noticing these things, I began looking more closely at other aspects of the hotel and noticed that the elevators were quite old and had not been cleaned well either. The hallway carpets appeared dirty and were rippled from stretching - they are obviously old as well and not kept up.
This is the second worst hotel I've stayed in and I've stayed in a lot of hotels all over the world. I would never recommend this hotel to anyone or stay here or in another Fairfield Inn again. When you can't even sit on the chair in the room because it is so badly stained or touch the tops of the furniture because your fingers will stick to the top, it is pretty bad.