7. Psycho II (1983) - 23 Years
There are a few "classics" on this list that were never allowed to be left alone, and Alfred Hitchcock's 1960 Psycho was one of them. It seems that Hollywood today is no different than it was three, four, or five decades ago. If there was a chance for more money, then they will milk that cow. Psycho II was one of three sequels to the story of a man haunted by the ghost of his dead mother. Story-wise, there was a little bit to work with here, but not much. Psycho II seemed to have followed a familiar formula: bring back one actor and surround him by relatives of the original characters to whose actors would or could not return for a slightly forced storyline.
Was it worth it? Hitchcock was a master story-teller and there was a reason he never touched the series again, because one movie was deemed enough. Granted this film was made three years after Hitchcock's death, so unfortunately he didn't have much to say in the matter. After 23 years there really has to be something new to add to a story to create another film, a change in the medium or a new outlook on the interpretation. But that is not the case here. Psycho II only continued the story but did little to nothing for deepening the narrative.