9. Alicia Silverstone as Barbara Wilson/Batgirl in Batman & Robin
Never mind the alteration to the character, Batgirl is Barbara Gordon in the comics, the daughter of Commissioner Jim Gordon and not Alfred Pennyworth's niece, Barbara Wilson, as she is in a film that's only benefit was being so bad that it eventually paved the way for Christopher Nolan's historic Dark Knight trilogy. The writing of the character is not very good as it comes across as someone who is added just for the sake of it and that is what happens when Barbara joins Batman and Robin as Batgirl toward the end of the film. Her addition to the Dynamic Duo in the film is forced in an already underwhelming plot.
Alicia Silverstone, who two years prior starred in the successful film, Clueless, was a popular and well-known actress due to the benefit of being the lead actress in the hit comedy. However, her performance in Batman & Robin does not do the character justice as Silverstone's portrayal is parallel with the writing of the character and the rest of the film which is not good.