The Ugly Truth (2009)

Abby Richter (Katherine Heigl) is a lovelorn TV producer who, despite a long and arduous search for the perfect mate, is hopelessly single. The battle of the sexes heats up when her employers team her up with Mike Chadway (Gerard Butler), an opinionated TV celebrity who plans to put Abby through the wringer to prove his own theories about what makes men and women tick.