Residence Inn by Marriott-Arlington

Reliably solid with a very friendly, professional staff. Were able to check in hours early with some room shifts on their part, helpful for tired airline travelers.
Quiet room with almost no foot/​car traffic noise, though hotel was reasonably full.
Housekeeping was fine and competent.
Easy access to interstate (though no interstate noise) and the two pro ballparks. The city runs a trolley to the ballparks that stops right outside this hotel, and tickets for it are free from the front desk.
Breakfast was competent but nothing to write home to Belgium about. Business travelers: you know what I’m talking about. There’s a coffee station so you can take coffee (with lids) out the door.
Recommended due to helpful staff, comfortable rooms and quietness.

I’m a huge fan of the Residence Inn by Marriott.
This particular hotel serves guests who have been displaced due to natural disasters or guests who are in town for some extended period of time. It really is an «Inn» in the classic sense of the term.
They have breakfast, lunch, and dinner daily in the clubhouse area… and the food is GOOD! Really surprised at how good it is. The rooms are cleaned consistently, and if there is a problem, the maintenance crew is on it quickly and efficiently (our A/​C was leaking when we arrived, maintenance arrived 10 minutes after our call).
The provide a great kitchen with plenty of storage, and a spacious «living room» area.
The pool area is clean and well kept with a basketball area as well.
Overall, it’s a fantastic place to stay if you’re in town for a while and on a budget. If there is a Rangers game, your prices may go up (especially if they’re playing another nearby team), but there IS a free trolley to/​from the game from this hotel and all neighboring hotels.
Definitely one of our first recommendations for someone staying in the Arlington area for a while.