Without that famous diner scene – and particularly the brief exchange afterward between the woman nearby and the waitress – it would simply be another fast-moving romantic comedy, overflowing with dialogue. The film centers on how “Harry” (Billy Crystal) and “Sally” (Meg Ryan)’s relationship develops. They've been friends for a long time, but they always dated other people. As we watch them experience various failed relationships, it becomes clear that approach isn't working, and they return to the same question. Would having sex damage their friendship? The story unfolds over a considerable period, which gives Rob Reiner the opportunity to structure the comedy in episodes and introduce new romantic partners for viewers to enjoy, dislike, or simply acknowledge as the predictable ending approaches. While the writing is occasionally clever and sharp, there’s just too much of it; even though Ryan and Crystal have some chemistry together, I found the entire movie rather transparent. It's not an unpleasant experience, and I realize my view isn't shared by many, but ultimately this feels like a typical showcase for two performers who are moderately skilled, one of whom is exceptionally good at saying "yes" repeatedly.

Source on TMDB