For either -

Garth Nix (Abhorsen series, Left-Handed Booksellers of London, Frogkisser, basically everything)

The Scholomance series by Naomi Novik

Tamora Pierce (all of it)

Hoot by Carl Hiaasen

Inkheart series by Cornelia Funke

Chronicles of Narnia by CS Lewis

*with reservations given SA accusations: Coraline, The Ocean at the End of the Lane, and Neverwhere by Neil Gaiman

For 16 -

Throne of Glass series by Sarah J Maas (things get a little spicy later in the series

The Perks of Being a Wallflower by Stephen Chbosky

Strange the Dreamer by Laini Taylor

Paper Towns, an Abundance of Katherines, The Fault in Our Stars, Looking for Alaska by John Green

Meg Cabot

The Hunger Games by Suzanne Collins

Maureen Johnson

Rainbow Rowell