Greenthumbz, those are gorgeous pics! I've heard that there are a couple of trees that are not native to North America but are used by significant numbers of native insects. 1) Malus/Crabapples - native, hybrid, or exotic, Douglas Tallamy's book stated that the leaf chemistry is so similar that North american insects will use all species. This certainly bears true in my experience. I've got lots of crabs, a few specimens and a crazy wild thicket full of them in back,and they are bird magnets, not just for the fruits in the fall but for the nectar and insects in spring and summer. 2) Picea abies/Norway spruce - don't have any personal experience, but was told this by an ornithology student at Cornell who was doing a study on the subject

Purple flowering raspberry (virtually thornless) Drooping Leucothoe. See them in the DC arboretum.

If oaks doing good there native kalmias and rhododendrons should live there as well. If you'll go for the mix of evergreens and deciduous shrubs/trees, add clethras that will suck extra moisture, if any. I have combo of evergreens (kalmias + rhododendrons + azaleas + leucothoe) and deciduous shrubs( kerria + iteas + clethras + buttlebrush buckeye + hydrangeas paniculata) in area where water could stay for a week or so in a spring and for couple of days after the heavy rain in a summer and all of them doing GREAT. Note: kalmias, rhodies and azaleas planted high, probably 7-8" above soil level. If you will be willing to settle for non-native, but very fast growing screening tree, you might be interested in Leyland cypress (Cupressocyparis leylandii). Research it well and plant at your own risk as most likely you'll have to prune it more often than you may expect.

Thanks for all the suggestions! We do have deer. This year for the first time I tried Liquid Fence, which was 100% effective in warding them off... this is the first time they haven't chomped on all my hostas. But I'm not sure if it would work to protect larger trees/shrubs. Rhododendron is one idea, though... we have two large plants on one side of our house, and they've never been touched by deer, but that may just be because they're right next to the house. They have grown quite rapidly and may be good for filling the bare spots where we don't need something very tall. We have acidic soil and they thrive. The neighboring house is at roughly the same level as ours, but our biggest area of concern is actually an elevated area in which the neighboring property juts almost in front of our house... the neighbor's property at that point is at road level, while our house is set both back, and down considerably from the road. There is no perfect solution because to provide good screening in that area we'd need to plant 20+ foot trees down on our property. Sigh. There used to be woods up at the road and a new neighbor moved in and impulsively removed them up to and possibly over the property line, in order to use the space for purposes which violate the zoning ordinance. Now there is just a useless bare spot. (Better bare than filled with junk, though.) We have transplanted some white pines elsewhere, and they do grow quickly, but they get leggy/spindly and don't provide much screening until they have huge trunks. Spruce may be ideal... tall and thick. I just haven't liked their uniform shape. But I will look into both those and the Cypress. Thanks!