With all this talk about how rare recordings of Sesame Street are or might be, it makes me wonder what episodes were recorded off PBS by the most people. Would be hard to determine. And I'm not counting recordings off Noggin or later cable broadcasts (where more of us would want to record). I'm sure many of the more important/heavily promoted ones (like Maria and Luis' wedding, Gabbi's birth, Slimey landing on the moon, the hurricane episodes) got recorded by a lot of people during their original broadcasts (though I don't think anybody recorded episodes 1839 or 2096 when they premiered, but fan recordings from that era are a little more scarce than in the late-1980s and later). With uneventful episodes, fans were likely just recording at random, or maybe they were trying to record as much as possible, but I'm sure that a lot of the episodes in tape trading circles were only recorded by one or two people who happened to be able to make copies for other fans and/or uploaded online in some compacity.
For the last few years, I've noticed that while fan recordings of late-1970s/early-1980s Sesame Street is scarce, there seems to be plenty of fan recordings of other television programming at the time, particularly specials and guest appearances (including A Special Sesame Street Christmas and A Walking Tour of Sesame Street). Perhaps people with VCRs in the early days of VCRs were more likely to record specials (that may or may not have a chance of rebroadcast) than a daily children's television show (since tape was expensive back then and there were so many episodes).
And would the kids watching, and maybe wanting to record episodes, have an understanding that the episodes they are watching might not be rebroadcast many times after? I feel like I sensed it by the time I was ten, I noticed after season 25 that they weren't rerunning episodes with the older opening and closing (though I thought they just replaced the opening, didn't think they would replace the end credits since the new ones had a regular scene of Big Bird saying "Sesame Street is a production of the Children's Television Workshop", when before the characters would say it after the credits in episode-specific footage) and had noticed that I hadn't seen any episodes with David since his disappearance had been explained.