near Reagan airport
The nearby choices will be mostly mediocre (except for the excellent tapas at Jaleo.) The best easy place for what you are looking for is Me Jana (as suggested above), right near the Courthouse metro stop. A bit upscale for Lebanese, with carefully prepared food.
However, if you are intrepid, I recommend taking a cab to either:
Eyo (Ethiopian) in Falls Church. In the same shopping Center is Al Jazera, a Yemeni restaurant. Eyo is easy to spot, but Al Jazera is completely hidden on the back side of this purely Ethiopian/Middle Eastern strip shopping center. I've taken my kids to eat there, so it's completely safe, BTW. At Eyo get the Awaze tibs, and at Al Jazera get the foul, fata, and the felafel.
It'll be easy for you to get a cab back: most of the people eating there will be cab drivers.
Or you can take a cab to Jerusalem, a Palestinian place in Falls Church. Get the masukhan or the makluba. If you have room for dessert, the om ali.
Depends how far you're able to travel. Metro will make it fairly easy to get to a number of places.
Bombay Curry Company in the Del Ray neighborhood of Alexandria (about 2.5 miles from the airport by cab) serves up some very good North Indian http://www.bombaycurrycompany.com/contactinfo.php try the chicken wings and butter chicken
Here's the website for Kohinor Dhaba, which is in Crystal City: http://www.kohinoordhaba.com/menu/
Harar Mesob, also in Crystal City http://www.harar-mesob.com/index.html Not the best in the region, but probably a darn site better than in most other parts of the country.
Neramitra in Crystal City (again, there are better places, but it's close to the airport) http://www.neramitra.com/Neramitra.htm
Afghan Kabob House near Courthouse Metro stop in Arlington http://www.afghankabobhouse.org/
Kabob Palace in Crystal City, already mentioned
Me Jana (Lebanese) also near Courthouse Metro http://www.me-jana.com/