Searching for best place... method ?

[Andrea P.]

I am trying to figure out a method to identify the best place (Metropolitan Area) in the US to find a "buy and hold" property.
A common method is to identify several parameters, score each of them.

I identified the following parameters:
Unemployment in August 2012 (from city-data.com)
Unemployment trend (from city-data.com)
Zillow Home index value
Zillow Rent index
Property managers accredited by BBB

Can you recommend a different method?
Can you add some other parameter to take into account?