I travel from Indianapolis to Mississippi about seven or eight times a year. For the last five trips, we've driven (10 hours) in a rented and fully-loaded minivan. In fact, any trip under five hours and I drive.
If you count travel to and from the airport, waiting and checkin times, and all that other crap, the drive is worth it.
And we stop in at Dreamland (Tuscaloosa) every time we pass it ;)
The problem is that you may spend more in gas than the cost of a plane ticket.
We stopped driving to New York for that reason.