You can tweak a bit down the line, but finding the right chemistry from jump with your main characters is important. "Seinfeld" hit the bullseye with Jerry, Jason Alexander, Michael Richards, and, after they wised up and boosted her to series regular, Julia Louis-Dreyfus. Estelle Harris was histrionic perfection as Estelle Costanza, while Liz Sheridan's Helen Seinfeld was a study in doting. Phil Bruns was first up as Morty Seinfeld. Once again, they envisioned a more passive paternal figure, one who could be easily steamrolled by Harris' Estelle.