I don't do parks, but from what my uneducated eye can see, the best in the region are at Snowshoe with Snow Time resorts coming in second.
Snowshoe is about 4 hours from Manassas via Corridor H, and Liberty/Whitetail are 1.5 to 2.5 hours depending on traffic. IMHO, Snowshoe early purchase season pass is about the best bang for your buck ranging from 215 to 377 depending ... see http://snowshoemtn.com/hotdeals.html.
Snow Time season pass for Liberty/Whitetail/Roundtop is in the 400-450 range if I remember correctly.
We usually purchase Snowshoe passes along with Snow Time Advantage cards [gives 40% off lift tickets] for our MidA skiing and always end up ahead for the season .. even a short one like this year.