Need more details, like your work location and family size.
For those with kids, it will entirely depend on your work location. Vienna is on a metro line and is pretty nice, but the buy/rent math always means you're renting an apartment or sharing a house with friends, in my experience. Places near Dulles Airport are getting much more dense - if you have a job near there, you can bike to/from work, housing, strip malls (grocery), and free parks. And the Udvar-Hazy Air & Space annex is way better than the DC version. Further out, Ashburn is getting more job opportunities and already has tons of housing.
To the south, Springfield has some potential and further out there is Woodbridge. The accessibility of parks depends on exact location - these are all fairly large 'areas' more than they are 'neighborhoods.' For example, if you work at Quantico, Woodbridge should be on your radar... but if you live/work in Reston, you might not even know where Woodbridge is.
For younger, single people, I recommend Tysons - the apartments there aren't any more expensive than the rest of NoVa, you can walk/bike to Metro, and there are tons and tons of jobs. I personally don't care much for Metro (it has gotten expensive) but everyone else my age seems to love it.
