9. Two-Face - Batman Forever
Even though Batman (Val Kilmer) and Robin (Chris O'Donnell) managed to foil The Riddler (Jim Carrey) at the end of Batman Forever, it really didn't matter given that they were still held at gunpoint by Two-Face (Tommy Lee Jones) with nowhere to go.
All Two-Face had to do to rid Gotham of its saving grace was pop a cap in the heroes and also Batman's love interest, Dr. Chase Meridian (Nicole Kidman), for good measure.
But instead, he waited around and let Batman remind him of his compulsive need to flip a coin for every life-or-death decision he makes.
And so, Two-Face flips his trusty coin, at which moment Batman throws a handful of coins at him, causing him to lose his balance while trying to spot his own coin and promptly falling to his death.
Given that Two-Face had evidently forgotten about his whole coin flip gambit until Batman reminded him, he was literally seconds away from pumping the heroes full of lead and becoming Gotham's ruling crime lord.