Bartlett
I had to jump in and post on this subject. I "own" a house in Bartlett and our property values are going up. Germantown and Collierville are the same I'm sure. I would also avoid anything near a mall (Wolf Chase/Cordova) because these areas seem to attract more crime than normal in this city. Explore areas around the Hickory Ridge Mall, the ex-Mall of Memphis, etc. and you'll see what I mean. Malls kill neighborhoods in Memphis. Any area that could possibly be annexed by Memphis should be avoided also. Definitely look in Collierville, Germantown and Bartlett. I don't know much about Desoto County, MS but I would look there too. I have family in Southaven and Olive Branch and they love where they live. Low crime rates, good schools, etc. Good luck.
My edit is to add that I grew up here. I was away from Memphis from 1990 to 1998. I was in the military for that time and didn't get back here that much. A lot changed in eight years.