Seinfeld show is as racist as it is funny. If you watch carefuly, nothing says "jew" in that sitcom more than their treatment of blacks. (African-Americans, as they like to be called). There was only one single instance where a black person portraied a normal human being, and that was in the episode in which George had to go to a romantic movie with Susan, while Jerry went to see some kind of action flick with this negro fella. But that scene, of them coming out of the theatre, only lasted few seconds.
On the other hand, blacks portraing mean, weird, rude, arrogant, attitude and complex carrying individuals (the precise perception of blacks among many caucasians communities [excluding violent and lazy - which would be too much even for Seinfeld show]). To give you just few examples: exterminator, person at the newstand George wanted to be a friend with, person George watched the Breakfast At Tiffany's with, woman at the South American clothing store where Elaine shopped, superintendent from Elaine's building who wouldn't let her move her new armoair in on Sunday, newstand guy who made George and Kramer buy lots of things just so he would break their hunder dollar bill, even George's co-worker who later got fired for oversleeping was a pretty arogant prick. Care to add more examples?