I think, at least as it comes across on tape, the most insane audience reaction to a bust out was that Box in Hampton '86. Honorable mention to Dark Star Hampton '89 and Stephen both MSG and Hartford '83.
Rude - as for why Visions was unflubbed while most other songs were mistake laden, Jerry would have been using the teleprompter early and often for Visions, but likely not at all for the songs he should theoretically have known cold.
The best Visions I've seen was done by JK at Terrapin Crossroads. Perhaps this was 8 or so years ago. Phil was doing a free bar set with JK and a few other musicians, and a transformer blew in the neighborhood shortly before the set was to start. When it became clear the power wasn't going to come back on anytime soon, they announced that they were scrambling to come up with acoustic instruments and that there would still be music played. Apparently there had to actually be a run to Phil's house to procure them. So the set was played to candlelight, the audience was fully respectful (what choice did they have? There was no vocal PA), and JK just nailed the most haunting Visions one could imagine. Just wow.