Carol, Hershel, Jimmy, and Frank from Walking Dead
Carol was supposed to die in Season 3, but the actress lobbied for her character to stick around (we didn't know you could do that, actually.) Hershel was supposed to die in a gory finale for Season 2, but an executive producer thought it was too violent and didn't want to lose too many regulars. Jimmy was kept alive, but only for two more episodes before getting devoured. Finally, Frank was supposed to die at the end of Season 1, but that season was so short (six episode), his death was pushed back to give his character more time.