Best way around this

Like Warcraft 3 when you select a unit a 2d box appears around the unit and his health bar is shown above.

The health bar can never be blocked behind a unit or object as it is shown through. It follows the unit and does not rotate with it.

I have thought of 2 ways, the first was to keep setting the health bars position to the targeted objects position. But this is by far the most CPU intense solution. The second was to parent the health bar to the object and keep setting its orientation back to normal, but you can see it change rotation at times and seems unprofessional. Does anyone have some ideas or have done this before?

The difference in performance, between that and parenting, should be negligible; Ultimately, the new position for the parented object would have to be calculated somewhere - either by you, or by the parenting system.

The second was to parent the health bar to the object and keep setting its orientation back to normal, but you can see it change rotation at times and seems unprofessional. Does anyone have some ideas or have done this before?
Did you try vertex parenting: http://www.blendenzo.com/tutVertexParenting.html

I thought this as well. The vertex parenting might not be a option with dynamically added objects so my best bet would be to refresh the position. Thanks for the help Social.