In which TV series is Newman a main character?

In which TV series is George Costanza a main character? In which TV series is Elaine Benes a main character? Who played Cosmo Kramer in 'Seinfeld'? Who played Newman in 'Seinfeld'? Who played Zack Morris in 'Saved by the Bell'? Who played A.C. Slater in 'Saved by the Bell'? In which TV series is A.C. Slater a main character? Who played Kelly Kapowski in 'Saved by the Bell'?