I was a little leery of staying at a hotel on the George Mason University campus, but I can whole-heatedly recommend the Mason Inn. It's very new and well laid out. The rooms are large, clean and well laid out. Front desk staff was very efficient at check-in and check-out. We were there for a corporate dinner event and the food and staff were terrific as were the bartenders. It seems like a little thing, but the chairs at dinner were actually comfortable. I've been to a number of ballroom dinner events where I could not wait to get up, the chairs were so bad.
It's on the perimeter of the campus, which is probably why it's nice and quiet.
I had checked the google before we left so knew how to get there, but several of our group got turned around looking for the entrance.
Another minor nit pick is that on Sunday they have a brunch that starts at 11. If you want to have breakfast at 10:30, as we did, you get the tail ends of the early sitting and they would rather you left so they could set up for brunch.
That said, a very good experience.

The Mason Inn was a great and I had the best cheese burger in the restaurant that I have ever had. You must try it. Can't wait to go back. The staff was friendly and courteous and willing to help. Gret experience around.

We just got home from a four night stay at the Mason Inn Conference Center and Hotel, and loved it! It is such a pretty hotel - both elegant and warm and inviting at the same time. The front desk staff was friendly and helpful, and the guest room we had was huge and really nicely decorated. And the beds - seriously comfy. Their housekeeping staff is awesome - not only was our room immaculate, but all of the public areas, like the lobby and elevators and bar, were spotless. Everything looked clean, smelled fresh, and every staff member we met was warm, courteous and professional. Will definitely stay here whenever I am in the Fairfax or Chantilly area!

We arrived a little after midnight and went right to bed. Staff was very friendly, efficient and helpful; room was clean and comfortable; and it was quiet. Had to get up early as well...bathroom worked nicely and was clean too. The buffet was good...some things could have been a little warmer but was very good and priced well. Check-out staff was just as friendly and efficient.