what is the closest good restaurant within walking distance of the hotel?
Lots of options, but my favorite is Kabob Palace - middle eastern buffet. Fantastic value, and the food is unbelievably good.
There is a Chili's a few blocks away with about a dozen ethnic restaurants on the street opposite...Italian, Mediterranean, BBQ, Sushi...etc.
We had breakfast buffet at the hotel every day and thought it was good. We also went to Legal Seafoods and it was good. It's a 15 minute walk, but the hotel has a shuttle to the metro and there are lots of restaurants near there.
You're within walking distance of dozens of restaurants so you've got your pick of food types. Legal Seafoods is close and they can't be beat for seafood options. There's a bistro literally across the street and the food in the hotel is actually very good as well.
Get an answer from Hyatt Regency Crystal City at Reagan National Airport staff and past guests.