Kurt asking the fans to sing "Happy Birthday" to Courtney during a concert. Love her or hate her, it was a sweet thing for him to do.
Most of the home movies that appear in Live, Tonight, Sold Out! show the band goofing around to an adorably cute level. Clips such as Krist hiding in a plane's toilet; "If this bird goes down, this is the safest place to be!", while Dave and Kurt try to pass the time. "The Traffic Situation" as Dave tries to look cool while pondering why the British drive on the left. And "Who's the jerk that had to rearrange everything?" as their kit doesn't fit in the van.
Kurt used to stay up until 3AM to answer fan mail. If that doesn't count, nothing does
The reason Kurt gave for not fighting Wal-Mart's Bowdlerization of In Utero's track list: A lot of kids live in small towns where Wal-Mart is the only place that sells music and holding the line would mean they couldn't get the CD.