Andy saving Serafine from commiting suicide by bungee jumping after her. The kicker? At first the bungee wasn't even tied on.
In the climax, when Serafine was fighing off the werewolves, she runs out of ammo. Does that stop her? No, she just takes the drug used to cause immediate transformations and just continues fighting.
The ending had Andy and Serafine getting married on the Statue of Liberty, which they plan on bungee jumping off. It becomes perfect when they accidentally drop the ring and end up having to jump after it.
Andy's fight with Claude taken to a subway. When Claude's dose of the serum runs out, he and Andy briefly wrestle for the last dose. Once Andy takes it, he literally eats Claude's heart out.