I'm hijacking the concept behind the other thread about Suddenly Susan.
Followup here if you think the 9/26 episode (Kramer falls in love with the woman Jerry is dating and Newman helps him out, Elaine meets a guy who gets a vasectomy because of her, George tries to find out if the foundation's board thinks he killed Susan) was the single worst Seinfeld ever.
I anticipate at least 100 followups. (OK, an exaggeration.)