The Delta Airport Hotel is one of the better ones in the city that I've been to. It looks nice, it's clean and it's directly across the street from the departure gate.
I've stayed here twice, once because somebody made me miss a flight (I've never missed a flight) and was impressed. The bar and restaurant here is first-class and even though I may have had more than the recommended daily intake, they were very patient and professional about everything.
The other time was just for a quick sleep before an early flight and again they surpassed expectations. The rooms are clean and fresh and everybody knows what they're doing. It's hard to find that these days and you will pay for it, but the airport Delta is definitely worth staying at.