Drive-by Truckers (Alt-country-rock.) Maylene and the Sons of Disaster (Southern Swamp metal.) That'll keep you busy for awhile.
That was some good good ol' down and dirty stuff, I like it.
Tim, I've been a Dropkick Murphy's fan for a while now. That's one show I really want to go to, I've even got the kilt!
Thanks for all the other suggestions everybody, and keep 'em coming if you've got any more. I'll sit down and check them all out when I get some time. For any of you fellow metal heads some of the ones I'd suggest are Down, Mastadon, and Clutch but I wouldn't really consider those underground. Some others I like that I would consider more underground are Sasquatch, Arson Anthem, Southern Flame, and Sixty Watt Shaman.