Batman Forever is perhaps best known for being the second most terrible Batman movie ever made aside from Batman & Robin. It is, in a word, spectacularly bad, marring the promise of seeing the Riddler and Two-Face banter onscreen with some truly terrible acting on the part of everyone involved, and a script that just defies any willful suspension of disbelief. Michael Keaton seemed to be unusually prescient of all of this, since the reason he gave for why he chose to bow out of the franchise was that he knew it was going to be terrible.
A great movie villain can elevate the hero and his journey. A great villain is the key to conflict, and conflict fuels an effective story, and an effective story is what allows a movie to linger on long after a movie has finished screening. This is all especially true in the realm of the superhero movie, where characters who can do impossible things need a bad guy who can realistically threaten them. All of the truly great superhero movies have a villain who balances the heroes, a sinister force who gives them something to fight.
This list is not about those guys. It’s about the other guys. The ones that suck.