I'm guessing if you're going through the Florida panhandle you're going I-10 through Texas, excellent choice (for sightseeing and food). I'm not from the Austin/San Antonio area so I don't know if they are THE BEST, but I always try to go to either Mi Tiera, or Pico de Gallo in San Antonio (if you go to Pico, ask for the special muy caliente salsa, after you're done with your meal so you can experience the best tasting fire you'll ever set inside your own mouth). If you want barbecue, if you can swing close to the Southwest side of Austin, go to the original Salt Lick, its a feast for the eyes as well as the palette, and set in one of the prettiest parts of Texas hill-country. They have a combo plate with Brisket and Ribs that I'd recommend.I'm not real big on Houston, but they say Gatlin's is pretty good barbecue. Try to drive through the Davis Mountains in the daytime (far west side of Texas, at least 10 hours from when you enter on the east side), its beautiful. Then on to El Paso. You're on your own in El Paso, but I've eaten some tasty Mexican food there, just don't remember where it was, I'm sure Yelp will have some good suggestions. Anyways, enjoy yourself, its a LONG hall across from east TX to El Paso, probably 15 hours with a couple stops.If you are going to head North up toward Colorado in Texas, then you'll probably go right through Dallas/Fort Worth. Just let me know what kind of food you want and I'll give you some recommendations since I eat all over the metroplex. that's not the prettiest drive, but the food choices can make up for it LOL