Harry Potter, although I don't think it'll be remembered for as long as Star Wars, or something like that. It was all one massive fad, and I can't see the books being remembered in the way that LOTR or TCON are. I work with young kids and none of them know what HP is, yet they know what Star Wars is, and they know The Hobbit.
The Hunger Games isn't that good so idk if that'll be remembered (too serious no charm!). Twilight is another fad. And Divergent shouldn't even be in the poll.