Well my first question is who are you buying this SFR for? Student from ASU, retired person, moderate income working person or anybody off the street? Who do you want to rent to? I think this will tell you where you want to buy.
I think the most dynamic and stable area in Maricopa County is the East Valley area, i.e. Chandler, Mesa and Tempe. You may not immediately see some of the smoking deals that you'll find in other areas, but if you look you can find them.
My pick would be Chandler, East Valley for any kind of investment.