Hotel: Washington Marriott Wardman Park
Would I stay again? Yes but would not be my first choice.  It is a huge hotel with tons of event space.  I prefer something smaller.

Restaurants:

Dinner: La Tomate Bistro
Would I dine again? Probably not.  The food was good but the service was absolutely terrible.

Dinner Day 2:  China Chilcano
Would I dine again? Yes, Yes, Yes.  All the plates we had were awesome.  Surprisingly, my favorite was the cauliflower.

Dinner Day 3: Bistro du Coin
Would I dine again? Yes, Almost every year I attend a conference at the Washington Hilton right up the street and the food is consistently good. Plus, who can turn down a great bowl of mussels?