votes received
Kudos to the above and 'in no particular order':

Miles Davis - "Miles in the Sky"
Steve Hillage - "Rainbow Dome Musick"
Neil Young - "Ragged Glory", "Live Rust"
Ozrics - "Pungent Effulgent"
Led Zep "II"
Gong - "Angel's Egg", "You"
Phish - any live Summer Jams on YouTube
Dylan - "Blonde on Blonde"
Thievery Corp - "Sounds from the Thievery Hi-Fi"
Zappa - "Absolutely Free", "Hot Rats"
Mike Oldfield - "Hergest Ridge", "Ommadawn"
& most (live) Dead "Dark Star(s)" & "Eyes...."
+ checking out the recommendations here...