Best theater experience I've had by far was seeing The Descent on release. In that crucial mid-movie moment, the whole theater freaked out, and after things settled down I saw someone climbing back over the seat they'd apparently jumped over when it happened.
I didn't go to the theater for a few years due to both the pandemic and a new baby. When I did return for the first time last year, I was truly shocked at how many ads there are now at the major chains before curtain draw. It used to be ads before showtime, then trailers when the lights dimmed at showtime. Now it seems like there are just as many trailers as there were before, but intercut by an equal number of ads, so the time between showtime and actual movie start is ridiculous.