Marking its 25th anniversary this week is "When Harry Met Sally," which many viewers consider the best romantic comedy ever made. Certainly, the film (released on July 12, 1989), deftly directed by Rob Reiner, smartly written by Nora Ephron, and indelibly acted by Billy Crystal and Meg Ryan, is the most influential romantic comedy of the past quarter century. Virtually every rom-com since has borrowed from its witty banter, its urban setting, its soundtrack both modern and nostalgic, and its neurotic-yet-lovable leads.

Of course, "When Harry Met Sally" also owed a debt of influence to Woody Allen's romantic comedies about talky New Yorkers, as well as to dozens of other rom-coms, going all the way back to the road-trip antics of Clark Gable and Claudette Colbert in 1934's screwball classic, "It Happened One Night."

There are a lot of great romantic films that go to such dark places (from "The Apartment" to "Eternal Sunshine of the Spotless Mind") that I'm not sure they qualify as comedies. Others, particularly in recent years, make me despair that no one knows how to write a good romantic comedy anymore. But there are some gems, films viewers keep turning to over and over, whenever they want to laugh and to fall in love vicariously all over again.When Harry Met Sally