Scott Pilgrim vs. The World (2010):

As bass guitarist for a garage-rock band, Scott Pilgrim (Michael Cera) has never had trouble getting a girlfriend; usually, the problem is getting rid of them. But when Ramona Flowers (Mary Elizabeth Winstead) skates into his heart, he finds she has the most troublesome baggage of all: an army of ex-boyfriends who will stop at nothing to eliminate him from her list of suitors.