The Offspring San Berubin tape
I'm sure everyone here has heard of the San Berubin tape of the Offspring in 1987; the earliest known footage of the band in concert (to my knowledge).
It's nice for the historical value, but the tape is badly degrated, to the point of being nearly unwatchable. It's in grainy black and white, and the audio is extremely muffled. Though the worst part is various gaps, which are caused with age in the tape.
This may not be new, but it's still a new discovery for me:
Apparently, the crappiness we've seen all around the internet is merely a degraded copy; the original tape is still out there in decent shape. The audio and video are excellent compared to what we previously had available. Best of all - no skips. Unfortunately, the only video that's been released is Tehran (an early take). I've found no signs of the rest. But at least this gives me hope that it's still out there.
Also, this is The Offspring performingm not Manic Subsidal, as this is 1987. I'm not able to confirm or deny the early name of "Iran" for their performance of [what would become] "Tehran," though.