Trying not to repeat any previous suggestions:
Grateful Dead - Reckoning -- One of their only commercially available acoustic albums, and my all-time favorite Dead album. Never get tired of it.
Velvet Underground - Live MCMXCIII - From their short-lived late-90s reunion. Great DVD too.
Dave Matthews and Tim Reynolds - Live at Luther College. Just 2 guitars and some blazing licks.
Bob Marley - Babylon by Bus
Sting - Bring on the Night (although it's starting to feel dated to me)
And numerous Phish albums - too many to mention. I've got one where the play the Beatles White Album in its entirety.
