Shaun of the Dead (2004)

Shaun (Simon Pegg) doesn't have a very good day, so he decides to turn his life around by getting his ex to take him back, but he times it for right in the middle of what may be a zombie apocalypse. But for him, it's an opportunity to show everyone he knows how useful he is by saving them all. All he has to do is survive, and get his ex back.