I meant plot in series.

Neither and both.

In my library, the YA section is this and ONLY this. I hate it.

I can't even list. Movies/books like this are everywhere!

Both. Every book I read is about a boy/girl saving the world.

....Edward's hardly popular though. People kinda ignore him actually :/

Girl moving to new town is more of in fanfiction. Or maybe I just haven't read many romance series.

If based on that sentence alone? Both. But I pick twilight because the story about werewolves/vampire are overused. Trueblood, vampire diaries, teenwolf, wolfman, a lot of novel and manga... Etc.