The orgasm scene was filmed at Katz's Deli, an actual restaurant on New York's E. Houston Street. The table at which the scene was filmed now has a plaque on it that reads, "Where Harry met Sally...hope you have what she had!"
In an interview with National Public Radio on November 2, 2004, screenwriter Nora Ephron credited Meg Ryan not only with the idea of faking an orgasm in the famous restaurant scene, but also with the idea of setting it in a restaurant in the first place.
The quote, "I'll have what she's having," was not only voted #33 on the AFI's list of "Best 100 Movie Quotes in American Film," as well as the only quote on the list to be spoken by a non-professional actor (Rob Reiner's mother, Estelle Reiner, delivered the line). It was also the only dialogue line ever delivered on film by mother Estelle.
As a sixteen year old, seeing that movie scene at the flicks really shocked me, as I totally didn't expect it. Up to then, the movies I seen on TV had happy endings.
Not a favourite as in best-loved, but a favourite as in momentous.