There are certain kinds of film franchises, especially if you consider trilogies. First, there's the kind that begins with the first film, which is a huge success. It's followed by the second film, which is an equal or even greater success. But when it gets to the third film, the series generally falters. Specific examples of this first kind include the Godfather films (1972, 1974, 1990), the first three Shrek films (2001, 2004, 2007), Pirates of the Caribbean (2003, 2006, 2007), Star Wars (1977, 1980, 1983), and Spider-Man (2002, 2004, 2007).
Then there's the (rare) kind that starts with the first movie, again a huge success; followed by the second movie, equally or even better; and the third film, even more better. This type of films series is the kind that understands progression in story and character development, as well as what great movies and stories should be. Key examples in this category include the Lord of the Rings trilogy (2001, 2002, 2003) and the Toy Story movies (1995, 1999, 2010). A latest example that could potentially fit this category is Christopher Nolan's upcoming Batman sequel The Dark Knight Rises (due out summer 2012).
And there's a third (but not final) kind that, again, starts with the first success, but then takes a falter with the sequel. Then, for one reason or another, the third film in the series makes a rebound, intending to be as good as or better than the first time around. Specific examples in this category include the Indiana Jones films (1981, 1984, and 1989) and the Back to the Future trilogy (1985, 1989, 1990). A latest example coming out this summer could potentially be the Transformers sequel Dark of the Moon (due out July 1, 2011).
More info coming soon from yours truly,