I am trying to hide my air conditioner unit. What plants can I place around the unit that will not harm it, nor the unit harm the plants?

That all depends on the air conditioner’s location. If there were a large planting area, you would be better served to distract the eye from the unit with a mixed planting of woody ornamentals and tall grasses, as opposed to drawing attention to it with the ubiquitous soldier course of evergreen shrubs. Always allow a constant 3- to 4-foot minimum clearance around the unit for the inevitable maintenance and for proper airflow. Now, if extra space is at a minimum, such as your condenser being adjacent to the patio, it would be better to have a screen, such as vented fence sections surrounding the visible sides. Dry-set the posts so the sections can be removed for servicing. If done well, it would add an attractive privacy screen effect as opposed to a cover-up.