A frequented spot for many of the 20-somethings in Northern Va. They offer dining and a tent-enclosed back patio, which I do not recommend visiting in the winter. The food is good, but a bit over-priced. I would go there for the people and the drinks, and opt to eat somewhere else.
There is a band there 5 out of 7 days a week. The place is a bit on the small side, but very popular and a great place to meet people. They have a small dance floor in front of the stage, and standing room up by the bar.
Parking is scarce unless you want to park at the conveniently located parking garage right across the street (well worth the $5). If the crowd is not up to your liking, you can walk across the street to another bar (Mr. Days)if the line isn't too long.
My recommended night to hit Clarendon Grill is Thursdays, but always go early or you will be stuck in a line for at least 1/2 hour.