Anchorhead said:
Indiana Jones And The Last Crusade.
The Good, The Bad, And The Ugly
The Dark Knight Rises.
Last Crusade and TDKR are weaker than what came before, but I have to admit they do make a decent fist of wrapping things up nicely, although there isn't any plot to wrap up in Last Crusade, as the Indy Trilogy are all self contained films. TDKR doesn't have much to wrap up either, as few characters crossover the 3 movies, although the League of Shadows storyline comes full circle.
Where as ROTJ brings all the characters from all the movies and all the threads together in one neat bow IMO
The Good, The Bad, And The Ugly, although excellent is just a third movie (as has been said above). It's not the conclusion of a third part story.... plus arguably it's a prequel ;-)