How about "The Band' and "Graham Parson".
The top three by a wide margin and in order of greatness are The Allman Brothers Band, Lynyrd Skynyrd and The Marshall Tucker Band.
ABB's, "Live at Fillmore East" is a masterpiece by any standard.
As a Georgian let me just throw in couple of others: The Georgia Satellites, Drive By Truckers, The Black Crows, and The Atlanta Rythym Section. (REM... definitely not).
BTW, I saw Hank III this weekend and all I can say is: WOW. The band consisted of a steel guitar, a fiddle, a drummer, three guitars and a stand up bass, playing what I would describe as heavy speed metal rock. Now, that's southern rock!
There is great live music in Athens, Ga... so y'all stop on by ya hear.