I used a place called "A Apple Appliance" a couple of times over the last few years for dryer repair and they have been fine. When I used them I thought they were in Fairfax City, but now the only listing I can find for a company with this name is in McLean. I realize the above is probably totally useless now that I have typed it but may it will help.
Whoever you get a recommendation for, look them up here to see if they have an abnormal amount of complaints filed against them:
http://www.fairfaxcounty.gov/consumer/complaint_history.htm
And if anyone could recommend a vacuum cleaner repair place that would be cool too (busted power cord retractor).