If you want a fast growing one that will quickly take over the whole hedge, then a running bamboo will be great. They are evergreen too so it'll block the eyesore year round. Of course you'll need to do the extra work with root barriers though. You can also plant forsythias which are also fast growing and takes only 4-5 years to become 8 feet high. I wouldn't recommend arbovitaes or trees in general because if one tree becomes diseased then it usually spreads to ALL of the rest of the trees and it will be a pain to dig and take out.

Show us what you have in a picture. Show an overall scene as much as possible ... one that illustrates why you are bothered by it.

I would assume the 'bothering' is just the monolithic height of an 8' wood fence - that's a BIG fence!! Especially when paired with a smallish, one story(?) house on a smaller piece of property.

If you have enough room for it, a deep planting bed with a mixed shrub border along the fenceline would work well. That is a far more aesthetically pleasing presentation than just a single type shrub or tree along the entire length. In your zone there are many broadleaved evergreen shrubs you could use that grow to an appreciable height, many of which offer showy flowers. Add a few deciduous shrubs for additional flowering or fall color and you've got the problem solved.

If you don't have the room, then we need to rethink the approach and photos are needed.

Photos will definitely get you better suggestions than without, so please add some to the thread, especially ones taken from where you will be viewing the fence such as from the patio or from the kitchen window. An overview of the entire thing would be useful as well.

You will want to focus on both the short and longer term since gardens do grow and change over time. So something like annual vines for a few years with shrubs planted to fill in over time might work. If it is currently just raw wood color, staining it a less obtrusive shade might help it be less in-your-face in the short term.

Running bamboo is a perfectly acceptable screening plant, provided it is planted with a proper containment system. I use it often in my designs. The other alternative is a clumping bamboo, which needs no containment system but is slower to spread and provide a full screen.

I agree that running bamboo is perfectly acceptable and requires a root barrier in most cases where it is used. Until moving to Florida my knowledge of clumping bamboo was only theoretical. I have seen that it is potentially as scary as running bamboo but in a different way. The clump footprint "swells" in diameter ... but it can swell to over 30' of incredibly dense, impenetrable forest. A person could walk into a "forest" of running bamboo, but one could barely reach their arm 3' into some masses of clumping bamboo. None of this is to suggest that bamboo is the ticket for this situation. Impossible to say what the solution is until we see pictures.

Well, even though you have regrets - congrats - I've never lived in places where 8 foot fences were allowed - we're always limited to 6 foot. If you don't have a huge backyard - then consider vines that are hardy in your area. They'll take up less width than shrubs and if you train them could look lovely. Climbing roses also come to mind - you just have to be careful not to plant something that will bring down the fence (wisteria) and consider whether deciduous is ok with you (if you're not out in the yard much in the winter does it matter if your chosen plants have no leaves then?).

I submit that hedges or bamboo will give you just as much grief as the fence, maybe more. Too monotonous. And bamboo is very messy. If you think of the fence as the background of a painting, creating a beautiful, though spare, scene in front of it will put it to good use. Place a sturdy trellis at a focal point of the fence (center?) and grow a delicate vine -- not a monster that will take over, but maybe a clematis or similar. In front of that, possibly place a birdbath or simple drip fountain surrounded with some easy-to-grow flowering and foliage plants to fluff around it on either side and along the fence, and include some plants with tall spiky leaves for contrast. Voilà, you are at peace. If you need more coverage (we don't know the expanse of the fence) place the trellis/vine at intervals, or break up the monolithic feel with a couple of very large pots with standards in them (shrubs or small trees trimmed to grow a single trunk and allowed to branch out higher up). If necessary, paint the fence a color that will contrast with and show off your plantings. (See photos)

a mixed shrub border along the fence-line would work well. That is a far more aesthetically pleasing presentation than just a single type shrub or tree along the entire length

Absolutely. A hedge in front of a fence would be redundant.

well, I would create a stunning fence:

We also did this to electrical boxes to make them fit into our landscape rather than be an eyesore.

You guys are awesome. Thank you so much! I will have photos soon!