When record store owner and compulsive list-compiler Rob Gordon gets dumped by his long-time girlfriend, Laura, because he hasn't changed since they met, he revisits his top five breakups of all time in order to figure out what went wrong. As he examines his failed attempts at romance and happiness, the process finds him being dragged, kicking and screaming, into adulthood.

Ally Darling is realizing she's a little lost in life. Her latest romance has just fizzled out, and she's just been fired from her marketing job. Then she reads an eye-opening magazine article that warns that 96 percent of women who've been with 20 or more lovers are unlikely to find a husband. Determined to turn her life around and prove the article wrong, Ally embarks on a mission to find the perfect mate from among her numerous ex-boyfriends.

College coeds in New York City, Al, the son of a celebrity chef, and Imogen, a talented artist, become smitten the second they lay eyes on one another at a bar. However, the road to happiness is not a smooth one. Outside forces, including a predatory porn star who wants to lure Al into her bed, threaten to pull apart the young lovers before their romance has a chance to really flourish.