The Best Live album

Luther Allison -- Live in Chicago (excellent blues)
Dee Dee Bridgewater -- Live at Yoshis (proves why she's still one of the best singers in modern jazz, and you can tell she had fun making it)
Keith Jarrett -- Live at the Blue Note
Allison Moorer -- Show (some of the songs on this one will knock your socks off)
Allison Krauss and Union Station -- Live
and if you liked that one try Rhonda Vincent and the Rage -- Ragin' Live (award-winning bluegrass singer with one hell of a voice)

Live Dead / nuff said!

Tower Of Power "Live And In Living Color" - absolutely rocks on vinyl, though I have never heard it on CD.

I second Swingman with his suggestion of Luther Allison Live in Chicago. Best bang for the buck blues album out there and some of Luthers best stuff. For sound quality I must go with alice in chains unplujgged

Keith Jarrett at the Blue Note, John Mayall (with Room to Move - can't remember if that's the title), and The Allman Bros. at the Fillmore.