I know you don't want to go too big, but if I were you, I would plant Green Giant Arbs. In around a decade or so, they would mostly block your view of those ugly houses...

No, GGs will get to 30-50', and about a third to half that wide, so would definitely overcrowd the yard. If you want evergreen, tall blockage, then the Thuja cultivar(s) 'Emerald Green', 'Emerald', 'Emerald Beauty' or 'Smaragd' would be your best bet - they all will grow to 12-15' x 3-5', and will fit in much better. I am not sure if these are different names for the same cultivar or are actually different ones, but they grow much the same.

Hollies can be left to grow or be shorn/pruned to the size you want, with the addition of berries as long as you have at least one male tree - their disadvantage lies in the prickly leaves - they do lose them and the prickles are no fun to meet barefoot! They WOULD discourage any prowlers from going through your yard.

If it were me, I would not get 5 of the same of anything, except for a hedge effect, and even then, except for blockage of ugly or intrusive sights, I would go with a mixed hedge - if one plant dies, you can easily replace it, without suffering through the "missing-tooth syndrome/look" for the next several years.

I would go for shrubs that flower at different times of the seasons, for berries, for foliage or interesting branch color or structure to give winter interest. Most of the KnockOut roses seem to be hardy and trouble free, flowering from about now to frost - they grow to about 4-5' x 4-6', but can be pruned to stay smaller - they do have thorns, but not nasty ones. They seem to stay just about evergreen, as well, for me here.

The yard certainly looks big enough to support a small tree such as a redbud, a crabapple or a dogwood, even one of the smaller maples, and the shade would be nice in summer. Planted to the southwest or the south of the sitting area, it could be very pleasant. Putting in an arbor or pergola over the sitting area, possibly extending it along the rest of the house, and planting it with vines would also give shade there and to the house.

It might be able to take several crape myrtles as well, selecting from the medium height or smaller growers - it would take time, but the taller CMs can get to 30' or more. Selected cultivars stay under 15', there are even dwarf ones that won't get bigger than 3'

One question I have is about water. It looks as though the houses behind you are on higher ground. Where does the water go when it rains? If it runs into/through your yard, then you need to plant for that, both in siting the flower bed and in choosing the plants.

I think you should plant bamboo.
Ask this question on the bamboo forum and they will advise you on exactly what varieties will do the trick for your situation.
You need fast, tall, evergreen bamboo that will aid in your slightly sloping yard.
Don't be afraid of it, it is easy to care for, unless you want something you will never have to bother with like an evergreen, which will not only grow slowllllllllly, but will take up most of your yard.
I planted an arborvitae emerald green about 3 years ago, I think it might be 3 feet tall now.
By the way, there is also clumping bamboo, which will grow like ornamental grass, but never turns brown like ornamentals, and would also be great for drainage.
Whatever you choose to plant, goodluck!

Look at the Chindo Viburnums. They're evergreens and have a nice waxy look to them. Also supposedly produce white panicles of small flowers in late spring. Grow to about 12-15' high and 5-8' wide. Relatively inexpensive too. Win-win situation...look good, adapt well, and cheap.

Personally, I would move those junipers and incorporate them into the border. They are going to eventually get way too wide and take up too much of your lawn. If you are trying to create an entryway feel into that area then consider an arbor with some bushes planted on either side of it that connect to the fence bed and a planting bed along the house respectively. I would create a curve to the bed line that is no narrower than 3 feet at the absolute smallest part but I would make it much wider at the ends (front bed incorporating that tree and in the back I would make a larger bed in the corner. Play with the garden hose and lay it on the grass to get some ideas. (think serpentine) I would plant a tree in the back corner, I think you have more room then you realize. Keep lower limbs trimmed up as your tree grows so you get a nice canopy but can still move under it. I think a redbud or flowering cherry/plum would all work size wise. I would also plant a small tree off the corner of the patio, but you didn't ask about that. What is the tree up front near the fence? I also agree with dibbit about not doing the hedge row of all the same. A mixed shrub border would be nice and could give you color all year. Depending on size I would do either 1 or 3 of each as I like odd numbers. If you do three I would do them in a triangle formation rather than a row plastered against the fence.

Here are some suggestions--
Knock out roses, My favorite is still the original one.
Forsythia (these get rather big so only do one unless you are getting a dwarf variety, and plant it where you can let it get about 10' wide as these look best when allowed to weep) In spring my huge ball of sunshine is a beacon of spring, but then it becomes a huge green bush the rest of the summer so plant some pretty perennials in front of it. (homestead purple verbena is nice)
Wiegelia (there are variegated varieties as well as dark leaved choices all with beautiful blooms)
Viburnum, This is a subject onto itself, research your favorite varieties on this forum some are evergreen, but most are not. The flowers vary greatly as do berries etc.
Perhaps a Little Gem Magnolia in the back corner?
Indian Hawthorne is an old stand by, it is ever green and can look nice, but will never get as tall as your fence.
Why not plant something to grow on the fence or on a trellis against the fence such as a clematis or Amethyst Falls Wisteria, then plant some smaller evergreens in front of it such as Helleri Holly or the Indian Hawthorne?
Japanese Cleyera is another evergreen possibility
August Beauty Gardenias, or some of the smaller varieties such as 'radicans' would be nice in front of whatever tree you choose to plant.
If part of the border will not get too much afternoon sun then I would definitely include some Hydrangeas, some repeat bloomers such as Endless Summer or Penny Mac would be show stoppers.
And what southern order would be complete without some azaleas? Again avoid afternoon sun.

There are so many choices but I would work on a bed line first and start preparing the site while you decide. Look up Lasagna gardening and start prepping the site with newspaper and soil amendments so you don't have to dig up all that sod. You can spray it with round up first if you want, but it is not necessary if you put down newspaper thick enough under your amendments. the amazing thing I find is that people are often afraid to plant to much as they think it will make their yard look smaller, but it will actually do the opposite, so unless you need a certain amount of grass to have enough room for the kids playing football or something, I would take out quite a bit of that lawn. Here is a link that may be helpful.

Have fun! Post pictures of whatever you choose to do.

Here is a link that might be useful: creating a shrub border