1) Spider-Man: Far From Home, when Peter is "outed" as Spider-Man. One of two genuinely vital bits of plot development in all the Marvel end credit scenes.

2) The bit when Ant-Man gets stuck in the quantum realm after the snap, which is the other vital bit of plot development (I think on the end of Ant-Man and the Wasp).

3) Captain America on the end credits of Spider-Man: Homecoming. Sums up with satirical aplomb how superfluous most of these scenes are.

The rest I'm thoroughly indifferent to.