Locus Amoenus: All By My Shelf

I skipped yesterday's question because this is my first Halloween Bingo, so here we are on the next one.

I don't know how well this series fits into the "supernatural elements" category, but I'm going with Pullman's His Dark Materials. Barring that, Harry Potter.

I can't think of any purely horror series I've read and liked (I reviewed a trilogy a few months back that was absolutely abysmal), so I'll have to keep an eye out for other people's posts today, to get some ideas!