2. Superman IV: The Quest For Peace
The original Superman movie franchise is widely regarded as one of the greatest in Hollywood history. There is a reason that this honor only refers to the first two movies. While Superman III wasn't well-received, the fourth one was a complete disaster.
Superman IV: The Quest For Peace does often receive an honor of its own, though, and this is ending up on "worst movies ever made" lists. Not just superhero movies; worst movies ever. Unfortunately, there is just no way of arguing against that. Its production values are painfully low, with poor and gimmicky special effects that pale in comparison to the revolutionary visuals of the 1978 franchise-starter.
The movie's one shining light is the fact that Christopher Reeve agreed to return, but even the legendary performer acknowledged how bad this one was, stating after its release that he regretted taking part in it.
I hate placing this movie on the same list as Batman and Robin, because at least that movie is fun and entertaining (and had appropriately high production values). Superman IV: The Quest For Peace is hard to watch because it's everything that the Superman franchise is not: Inconsistent and disheartening. It's such a shame that the iconic franchise came to an end in this way.