7. Batman Triumphant
What Was It: As Batman is a favorite to be adapted to film, he appears quite a bit on this list. During production of Batman & Robin, Warner Brothers was impressed with the dailies, so plans were immediately put in place for a fifth installment, to be called Batman Triumphant. George Clooney and Chris O'Donnell were contracted to reprise their roles as Batman and Robin and Joel Schumacher would have returned as a director. Nicolas Cage was in negotiations to play the Scarecrow with Harley Quinn also playing a part. Although not as the Joker's Girl Friday, but instead she would apparently have been combined with another DC character called the Joker's Daughter (who also claimed to be the daughter of Catwoman, Scarecrow, the Riddler, and the Penguin). Quinn would be the daughter of the Joker seeking revenge on Batman for the death of her father. Perhaps the most interesting casting, though, would have been the return of Jack Nicholson as the Joker. The plot would have involved Batman hallucinating the Joker as part of exposure to the Scarecrow's fear toxin. The elements seemed to be in place for Triumphant to perhaps be more along the lines of Burton's 1989 Batman, but given that Warner Brothers was impressed with the dailies from Batman & Robin, I imagine it would have involved no small amount of camp from Cage's Scarecrow.
What Happened: Batman & Robin's theatrical release. It's hard to describe just how much of a massive failure Batman & Robin was on almost every single level, both critically and commercially. George Clooney vowed to never again don the cape and cowl and even apologized for killing the franchise, as did Schumacher (although neither were anywhere near as culpable as the producers who forced the camp tone on the franchise in the first place). Warner Brothers immediately halted plans for Batman Triumphant and began to look for ways to salvage the franchise.