Dark Star - Grateful Dead (I have a version from a show in 72 of the date I'm not sure, but it is like 35 minutes.)
Terrapin Station from 5/7/77 @ Boston Garden
Probably Terrapin Station. ETA: But anything from that 5/7/77 show would be worth having. easily my favorite Dead concert. And I've probably listened to recordings of over 200.
This post was edited on 12/27 at 1:29 pm