ilovefuzz.com

Does it have to be delta? The Hill Country guys are good -- Junior Kimbraugh, RL Burnside, T-Model Ford, Cedell Davis.
Rory Gallagher is fantastic -- one of my favourites ever.
How about Hound Dog Taylor?

Kinda more traditional?
Big Bill Broonzy
Junior Wells

Slide? How about Mississippi Fred McDowell? Willie Baker, Fred McMullen, Tampa Red, Clarence 'gatemouth' Brown, Bukka White, Reverend Gary Davis,

New (as in recent?) try Seasick Steve. The North Mississippi Allstars are good too. How about Chris Thomas King? Sean Costello wasn't delta but good and recent. Black Keys!

post-Allman rock Southern? How about early Blackfoot? They kinda turned into a crap FM bland AOR rock band after a while, but the early stuff is pretty good for what it is (No Reservations, Flying High, Strikes, Tomcattin, Marauder, Highway Song Live).
Black Crowes
George Thorogood and the Destroyers
Gov't Mule
The Fabulous Thunderbirds

Eyehategod are from the south, but somehow I don't think they count

Loads of options though ...

Is Captain Beefheart out of the question?

I'm not of much help in terms of specific artists, but you couldn't go wrong with one of these: http://www.alligatorrecords.com/index.c ... State=play

Definitely Elmore James...

[youtube]http://www.youtube.com/watch?v=aKo80b-QfK0[/youtube]

Thanks so much guys! Really great suggestions - I've already tracked down a bunch based on these, and will keep using this thread as a reference for the mixes. It's also opening my own eyes to great old-skool and contemporary blues (a genre that I had sorta/kinda given up on - and unfairly, I now see).

[youtube]http://www.youtube.com/watch?v=u8FS2LxdmVc[/youtube]

While we're on the topic of Rory.

It will combine his desire for blues and our/your love for all things messy, fuzzy and noisy. Blues does not get much messier than this.