It seems to me that there aren't many good trilogies in any medium or genre. The three I can think of off the top of my head are The Godfather (the movies, haven't read the books), Star Wars (the movies) and Lord of the Rings (both books and movies). It seems like there is a list of much longer movies/vidoegames and even book trilogies that start strong and then have a disappointing finish (The Matrix, Halo, Pirates of the Carribean, Spiderman just to name a few). Thoughts on why this or examples for/against?