Recent memory was a 70mm projection of Boogie Nights. The audience treated it like The Room or Rocky Horror and cheered whenever a new character came on screen. Laughed during the first porn scene. Laughed and cheered when Macy killed his wife and himself. It was mind boggling.
The irony was that was at a small indie theater, the next day I saw Interstellar IMAX re-release and the audience was immaculate.