You've Got Mail
The joke of Nora and Delia Ephron's screenplay is that the one, true love of your life may walk right past you on the sidewalk, and you'll never know it.
"...Nora Ephron. Starring: Tom Hanks, Meg Ryan, Greg Kinnear, Dave Chappelle, Jean Stapleton, Parker Posey, Steve Zahn and Dabney..."