Is there any other sitcom where the entire plot of an episode originates from a casual conversation or, as was often the case with Seinfeld, a tactless remark? Not really, and that's probably because other sitcom writers know better than trying to ape the show's successful gimmicks.
The Nose Job is practically all about George dating a woman with a huge nose, which prompts the excessively earnest Kramer that a little surgery wouldn't be bad for her. While the nose subplot advances, Kramer and Elaine also come up with a scheme to get their hands on a jacket he desperately wants, and Jerry is tormented by his sexual attraction for a vacuous actress he doesn't really like that much as a person.
For sheer irreverence alone, this episode is a Season Three classic, the scene where Kramer makes the nose comment standing out as a prime example of how daring Seinfeld could be (and still is, as a matter of fact). Jokes about body parts. Even the most inappropriate ones, always fare well (a lesson Larry David carried on to Curb Your Enthusiasm), and the way Michael Richards and Jason Alexander act around that event still has to be equaled (is it any wonder Richards won an Emmy for his contributions in this season?).
Plus, The Nose Job contains the most audacious and entertaining dream sequence ever: Jerry's brain and penis playing chess to decide whether the comedian should dump his uninteresting girlfriend or not. Not even Woody Allen in his early, funny years was brave enough to write a scene like that.