Live? Hmmm... If you can do without live, these will get you started:
Allman Brothers - Beginnings and Eat A Peach
ZZ Top - Tres Hombres
Lynyrd Skynyrd - Pronounced Leh-Nerd Skin-Nerd and Second Helping
Molly Hatchett - Molly Hatchett
38 Special - Wild Eyed Southern Boys and Rockin' Into the Night
All these bands have live albums and greatest hits collections. I tend to be an album purist.