Road trip advice- KY, TN, GA

[hayley]

I'm taking a ten day road trip with my boyfriend next week from Chicago to southern Georgia. We won't be staying very long anywhere, but I was wondering if anyone had any recommendations of places to see, the best place to stay, etc in these cities... I've got a good idea of what to do in Nashville, as I've been there before, but Atlanta & Louisville are mysteries!

Louisville, KY
Atlanta, GA
Nashville, TN

We are also planning on spending a day at Mammoth Cave in Kentucky- has anyone been there and has any advice for what to see / not to see?