I am, first-and-foremost, a Nancy fan, not a Freddy fan. When she died in Dream Warriors, she died to save those kids. When Freddy returned and killed all those kids in Dream Master, it rendered her sacrifice meaningless. So I utterly detest the later sequels, regardless of whatever merits they may have as films.
I just went through the Jason films for the first time recently. I hold similar sentiments in regards to Tommy Jarvis and Jason Lives. The films after that just feel pointless.