I'm a big fan of Combos while on the road. When I drive from West Virginia to se my folks in the Chicago area, I live off of Combos and Powerade. That's the key to a long road trip:
Combos
Powerade
cigarettes
loud music
The Dead are overrated no doubt. With the exceptions of "Uncle John's Band" and "Mexicali Blues", I don't find them to be listenable. "Casey Jones" is ok as well.