Lived in MEM for a little more than a year and I thoroughly miss it. Definitely have to move there with an open mind. Great culture...music, food, nightlife, it's all there. And of course affordable living. Plus no TN state income tax...
If you are single and in your 20-30s, I'd highly recommend living in either Midtown or Downtown. Yeah, sure there's crime, but I'd say none more than in any other major metropolitan city if you aren't careful or stupid.