Many moons ago, my fiancée (now wife) and I went to the cinema to see the "final" Indiana Jones movie, Indiana Jones and the Last Crusade. When we bought our tickets, we were told that there was some kind of special preview going on for a new movie called Weekend at Bernie's, and we could stay and see it for no extra charge. There would be an intermission in between films. It was like a 1:00 PM show and we didn't have anything else going on, so we decided to stay and watch both movies. Also, we got free posters for both movies.
Last Crusade is probably my favorite Indiana Jones movie, although that's largely due to Sean Connery. So that was cool, definitely a good time.
But imagine seeing Weekend at Bernie's for the first time, with no idea what's coming. The "twist" was bizarre, but then it became a thing, and indeed the whole point of the movie (which we didn't realize going in, of course). We were laughing our asses off the entire time. On the way out, I think there was someone asking us a few quick questions about it, and I don't remember specifically but I'm sure we rated it pretty highly. Just a crazy, dumb movie, but lots of fun, especially if you have no idea.