I'm a fan of the Dune books. At the moment, there are a bunch of trilogies on there, but it would be nice if they were all grouped under a meta-series of "Dune". It could then show them in order, too, as that isn't immediately obvious.

On that note, you have a bit of a mess with these - there is "Heroes of Dune" and "Heroes of Dune trilogy", one of them empty. Same with:
Legends of Dune
and Prelude to Dune