Easiest way to get to Falls Church, VA from BWI Airport (BALTIMORE)?

not including a car
thanks

Taxi.

B-30 Bus to Greenbelt
Green Line to Gallery Place
Orange Line to East or West Falls Church

{EDIT} Reversed order of travel; I see people do the bus/subway trip with one or 2 pieces of luggage and takes about 2 hours plus to go from BWI to Falls Church this way.

Taxi or Super Shuttle don't involve moving your luggage from one thing to another. I'd say that Super Shuttle is the best tradeoff between cost and convenience.

Next, I'd say is taking the MARC train to Union Station, red line to Metro Center and Orange Line to Falls Church (East or West). That, however, involves a shift.

Reverse Bob's route to get from BWI to Falls Church. It is the cheapest, but the bus can be hard to handle luggage on, and the timing is not always convenient.

295 to 695 to 95S

You can take an express bus from the BWI airport to the Greenbelt (green line) metro station. Take the green line to the red line, then transfer at Metro Station to the orange line. It would be about $5/person but it could take as long as 90 minutes.

Another idea is taking super shuttle, although I've not had good luck taking it (they're supposed to have no more than 3 passengers and they often load up the van) but it would likely get you there faster. The cost would probably be about $20/person.

Another option if you are looking at a cheap way to get there that avoids traffic:

Take the Amtrak bus to the Am track station at the airport (5 minute ride).

Take the train from BWI to Union Station.

At Union Station transfer to Metro. Take the red line towards Shady Grove for 2 stops. Get off at Gallery Place/Chinatown. (the metro map is at: http://www.wmata.com/metrorail/systemmap.cfm )

Transfer to the Orange Line going toward Vienna/Fairfax. Ride the Orange line to either East or West Falls Church.

If you are traveling during rush hour this will certainly beat the traffic.

Other options: Take a Super Shuttle, Taxi, or rent a car.