I purchased a home in Prince William county in 2004. Luckily my ca native wife pushed for us to leave so in march 2006, we sold our home and moved back to SD. We sold for 130K over our 2004 purchase price. Sadly the people we sold it to lost the home in 2009 and the current value of the home is 140K under what we purchased for in 2004.

I think anything inside the beltway is safe as well as the areas hugging it (all except PG County which is all ghetto).