After you leave NO, heading east, you will come to Biloxi/Gulfport - nice beaches, lots of casinos. Further down the road, Mobile - USS Alabama docked there. You can see if from the interstate. Right across the bay from Mobile is Daphne, AL, our usual stopping point for a night on our way to or from WDW. The staff at the Comfort Suites there is great. Excellent outlet mall in this area - but it's a bit off the interstate.
A bit further down the road is Pensacola, FL - beaches are a ways off the interstate. Further down is Ft Walton Beach, Panama City, Destin and a few other great beach areas on the Gulf Coast. White sugar sand beaches - really beautiful. Just watch out for the sharks and jellyfish.
By this time we are trucking along to get to I-75 and head south again. No stopping for us. Head south, then turn east on the tollway. Once we hit the Florida Tollway, we are looking for orange groves along the way. And we don't stop until we get to WDW.
Before you get to NO, near Lafayette, you will find the Hot Sauce factory (you know the one where everyone wears the ties with chili peppers on them). They have tours there. Once you leave Lafayette, you cross the Atchafalya Swamp basin - really cool - and you wonder how they built the interstate in this area. At Baton Rouge, continue on I-10 to NO, or skip NO and cut off a few miles and stay on I-12. I-12 joins up with I-10 near the east state line of Louisiana.
Hit the French Quarter (if you have kids, do it during the day to avoid most of the adult stuff). There is a VooDoo shop in the FQ that is kind of neat. There's a neat aquarium in NO. Check out some of the antibellum homes in the area. Neat. Also take a cemetary tour - lots of famous people buried there and the mausoleums are neat. Water table is too low to dig graves, so everyone is buried above ground in mausoleums or stone tombs. If you saw the movie Double Jeopardy, some of those scenes were filmed in one of the cemetary there. Ride a paddlewheel boat on the Mississippi River. And get some beignets - they are wonderful when they are fresh. Not like the ones that serve at WDW at Port Orleans. Get them from Cafe Dumonde.