For a lasting impression and year-round interest try evergreen shrubs. We are all familiar with hollies and boxwoods, the classic short hedges, the ones that reliably maintain there deep colors all year long. The reliability of evergreens is great for landscaping because it reduces the amount of maintenance required to keep an aesthetically pleasing garden.
If you want something a little more interesting than the monochromatic boxwood, opt for a plant that flowers and produces fruit. For instance, hollies periodically produce those lovely red berries (which also attract birds). Gardenias and Rhododendrons produce large fragrant blooms, and provide a little more interest than your standard evergreen.
If you want an evergreen shrub that has interesting architecture, try a juniper. Junipers are amazingly hardy and their habit varies tremendously from one cultivar to the next. Juniperus 'Skyrocket' grows 15 feet straight in the air not getting any wider than 18 inches. In this area there is a common ground covers varieity. They are a related to cypress but are generally much shorted and have very interesting, gnarled trunks and a fairly unpredictable habit.
