I have rosa rugosa along part of the road frontage of my
property.  They tolerate any road salt that happens to run
onto them and they produce delicious hips.  I've begun a
brushy hazelnut border along the back side of the upper
yard;  I'll continue with service berries.  Red and green
romaine lettuce are pretty low foliage plants for partially
shaded spots around the house or in the dappled sunlight.
Four varieties of raspberries border another edge.  In the
lower yard, pawpaws and persimmons are catching on with
white and black currents interspersed.  Kale has beautiful
ruffled foliage and can be placed in a cool spot for the
summer.  Low-growing varieties of thyme are great in between
stepping stones in a rock garden - they smell wonderful as
you walk over them and the fragrance diffuses into the air.
Other herbs work as well.  Chive blossoms are beautiful
purple and edible.  Edible flowers: petunia, most herb
flowers, nasturtiums, pansy, daylilies (new daylily shoots
make a tasty, mild addition to salads), and many more.
Blueberries have lovely red foliage in the fall - I have a
couple as foundation plantings with native acid-loving
plants like rhododendron and and juniper.  Walnuts are
planted away from everything; I hope to put in hybrid
Asian/American chestnuts soon.  (I gather from the
neighbor's small and rare stand of native chestnuts - my
favorite time of year!)  Northern hardy kiwis with pink,
green and white foliage will be climbing around a walkway
trellis.  A grape arbor makes a nice backdrop for a garden
bench.  We have an elderberry patch growing wild down below.