I-75 is a mighty long road through Georgia. However, I've found a few places to eat along the route.
In North Georgia, I'd recommend the Cracker Barrel in Kennesaw. It's around mile 271 at the Chastain Road exit. The restaurant is at the corner of Chastain Road and Busbee Pkwy.
In central Georgia, I'd recommend going into Warner-Robins and eating at Ladda Thai:
Restaurant Review: Ladda Thai in Warner-Robins, GA
It's off of Watson Road near the base.
In South Georgia, I'd recommend a quick stop at Fazoli's in Valdosta.
Restaurant Review: Fazoli's in Valdosta
It's right off the interstate in Valdosta.
Anybody else have some good recommendations?