We are really going to have to know more info. For example:

1. How much area is there? How wide can the plant/shrub/tree grow?

2. How tall can it eventually get?

3. Does it need to be evergreen?

4. If it can be a vine, is there a fence for it to grow on or can you make a fence for it to grow on?

5. Will you be able to prune, water, and maintain it on a regular basis?

6. Is there anything else you can tell us that might help?

Two that always pop into my head when I see this question: Leyland Cypress and Photina.

I'd still like to know more about the location and requirements.

Leylands and Photinia (correct spelling, in case you want to look it up) each have some problems you need to be familiar with before choosing them. Both of these are very overplanted and suffer from some serious pest and disease issues. Alternatives might be better.

Common Leyland problems include bagworms, Spruce Spider Mites, Juniper Scale, Maskell Scale, Minute Cypress Scale, Cypress Weevil, Bark Beetle Phloeosinus (less common), Spittlebug (usually only minor problems), Seiridium canker, Botryosphaeria canker, Cercospora needle blight, Phytophthora root rot, and Annosus root rot.

Photinia have a lot of reported problems also. Basically, just check out anything you see that interests you. Every plant is going to have some potential pest or disease problem, but some are much better than others.

well, its a strip about 40 feet long, just want to plant a row of something to block the view from the neighbors. Its full sunlight all the time and the ground is hard clay and a little rocky. I have a few leyland cyprusses i planted 4 years ago and they have not grown an inch and i have had bagworms on them