I got this idea when I realized that both movies I’ve watched this afternoon, Romancing the Stone & Johnny Dangerously, both had Danny DeVito in them. I then got to thinking that I should spend one Saturday watching six movies that connected one by one. I gave it some further thought and figured it didn’t have to be limited to actors, but also include writers and directors. Mainly because if I wanted to continue on this thread, I could move on to Practical Magic because Griffin Dunne stars as Tommy Kelly in Johnny Dangerously and directed Practical Magic. Hopefully, you get the idea. The real trick is figuring out a sixth movie that somehow ties back into the first movie.
If you were doing this in a library, you could add another layer of fun by doing it over a six week period and give a prize to the patron who could guess the connections between the movies.