We recently spent two nights at the Fairfax Hilton Garden Inn while attending a nearby family wedding.
On the plus side: our room was squeaky clean with standard, comfortable furnishings. In addition to a coffee maker, there was a microwave and a small fridge which would make storing and heating take out, etc a convenience.
We used Hilton HHonors membership points towards a free, cooked to order breakfast for two each day. The normal cost of the breakfast buffet is $10.95 per person and is a fairly good value at that price. Food was fresh and tasty with a large range of choices. The morning staff in the restaurant were more than pleasant and efficient as were all staff we encountered.
The hotel is really handy to Dulles airport which is within a 20 minute drive when the traffic is light.
On the negative side: this hotel has several large function rooms and seems to do a booming business hosting all sorts of events. Our room (#203) was located directly above the entrance courtyard to the function area as are many of the hotel's rooms. On our first night (friday) we noticed a large gathering of fairly mature adults partying away. When their function ended at around 11 pm, several of the group gathered on the benches in the courtyard and proceeded to scream and yell and laugh like crazy - this went on until at least 1:40 am. We like to sleep in a cold room and so cranked up the a/c to drown out the commotion. As the unit turned itself off when it periodically reached the desired temperature, we would awaken once again to the shrieking and hollering. I suppose we should have called the front desk and made a fuss but felt that would only add to an already uncomfortable situation.
On Saturday night, a large wedding was held in the same space. We clearly heard the thumping music which didn't particularly bother us while we were still awake and nervously waited for more nonsense from noisy revelers. We were pleasantly surprised when, at the stroke of 11pm, the music stopped and the guests quietly left the hotel. The rest of the night was silent.
So perhaps the function rooms aren't always a big problem, but I would strongly suggest that early to bed folk or light sleepers request a room on the opposite side of the building from the function area.
Despite the noise issue, we enjoyed our stay. We felt it was a good value and the friendly, courteous staff made up for the rudeness of a few party animals!