1989's Indiana Jones and the Last Crusade closed out the original trilogy of films about the adventurous archaeologist played by Harrison Ford. It's worth noting, however, that the title is up for interpretation. While it can be understood as describing Indy's last adventure, it can also refer to the final quest for the Holy Grail. For that matter, it could be a reference to the final quest of Indy's father, Henry Jones (Sean Connery), who spent his own life looking for the Grail. But whether the title was meant to refer to this being Indiana Jones' last adventure or not, it seemed to be exactly that for a long time. Steven Spielberg and George Lucas moved on to other projects, and almost two decades passed.
Then, of course, came 2008's Indiana Jones and the Kingdom of the Crystal Skull, in which a much older Indy faced communists and aliens instead of Nazis and mysticism. The film's reviews were surprisingly positive, giving it a score of 77% on Rotten Tomatoes. A fifth Indiana Jones film is in the works for 2020.
It's worth noting that Last Crusade is the only non-horror film on this list, presumably because like the monsters they feature, horror franchises are just the hardest to stop. Or it could be the opposite—that finality is more important to horror. For action movies, on the other hand, the emphasis is on moving forward, on winning. The Dark Knight Rises, for example, was written as an ending for that version of Batman, but it would seem weird to call it Dark Knight: The Final Chapter.