After lots of research, we chose Fairfax County after living in the Bethesda-Chevy Chase area for almost 12 years. Here's why:
(1) Lower taxes (for the record, I am a Dem). We were priced out of many places in MoCo -- when we were looking, we would think we could afford a house only to calculate the monthly payments and discover it was unaffordable because of state, county, and locality taxes. Even though we pay lower taxes in Fairfax, we have excellent municipal services, trach collection, schools, etc.
(2) Related to this, the fiscal management in Fairfax County and Virginia seems to be better. MoCo finances are a disaster.
(3) People are just plain nicer where we live. I found many (not all, certainly) people in Bethesda to be snobby, wealth-focused, and not interested in you unless you could not advance their interests in some way. I don't find that in Fairfax, even though there clearly is money here. I have never felt scrutinized for my stroller and fashion choices, which I definitely did in Bethesda.
(4) Drinking water is cleaner (see
http://www.washingtonpost.com/wp-dyn/content/article/2009/12/12/AR2009121202136.html).
(5) For those with comments about the Confederacy, have you been to NoVa lately? It is extremely diverse. My neighborhood includes white, AA, and Asian families. By contrast, my Bethesda neightborhood was all white.
(6) My vote counts.