I have noted the books commonly considered young adult with a '(YA)' and a '(MG)' for middle-grade and a '(NA)' for new adult. The ones marked '(Adult)' are explicit and not recommended for those underage.
Fantasy
A Natural History of Dragons by Marie Brennan
Emperor's Edge, The by Lindsay Buroker
Graceling by Kristin Cashore (YA)
High King's Tomb by Kristen Britain
Shadow and Bone by Leigh Bardugo (YA)
Throne of the Crescent Moon by Saladin Ahmed
Monstrous by MarcyKate Connolly (MG)
The Isle of the Lost by Melissa de la Cruz (MG)
Wings of Twilight by Hans Cummings
Death Sworn by Leah Cypess (YA)
Tymora's Luck by Jeff Grubb & Kate Novak
Stolen Songbird by Danielle L. Jensen (YA)
The Lies of Locke Lamora by Scott Lynch
The False Prince by Jennifer A. Nielsen (MG)
Terrier by Tamora Pierce (YA)
Silver Phoenix by Cindy Pon (YA)
Sabriel by Garth Nix (YA)
Seeds of Discovery by Breeana Puttroff (YA)
The Child Prince by Honor Raconteur
Falling Kingdoms by Morgan Rhodes (YA)
Shard Axe, The by Marsheila Rockwell
Falling Kingdoms by Morgan Rhodes (YA)
Shard Axe, The by Marsheila Rockwell
Sora's Quest by T.L. Shreffler (YA)
The Crown Tower by Michael J. Sullivan
Emerald Storm, The by Michael J. Sullivan
Wintertide by Michael J. Sullivan
Percepliquis by Michael J. Sullivan
Emerald Storm, The by Michael J. Sullivan
Wintertide by Michael J. Sullivan
Percepliquis by Michael J. Sullivan
A Wicked Thing by Rhiannon Thomas (YA)
The Wizard Hunters by Martha Wells
Poison by Bridget Zinn (YA)
The Thief by Megan Whalen Turner (YA)
Air Awakens by Elise Kova (YA)
Viper's Creed by T.L. Shreffler (YA)
The Dreamer's Curse by Honor Raconteur
Madly by Amy Alward (YA)
Frozen Tides by Morgan Rhodes (YA)
The Stepsister Scheme by Jim C. Hines
Kingdom of Ashes by Rhiannon Thomas (YA)
Truthwitch by Susan Dennard (YA)
The Goblin Emperor by Katherine Addison
Villains by Necessity by Eve Forward
The Cloud Roads by Martha Wells
Thorn by Intisar Khanani (YA)
Age of Myth by Michael J. Sullivan
The Thief by Megan Whalen Turner (YA)
Air Awakens by Elise Kova (YA)
Viper's Creed by T.L. Shreffler (YA)
The Dreamer's Curse by Honor Raconteur
Madly by Amy Alward (YA)
Frozen Tides by Morgan Rhodes (YA)
The Stepsister Scheme by Jim C. Hines
Kingdom of Ashes by Rhiannon Thomas (YA)
Truthwitch by Susan Dennard (YA)
The Goblin Emperor by Katherine Addison
Villains by Necessity by Eve Forward
The Cloud Roads by Martha Wells
Thorn by Intisar Khanani (YA)
Age of Myth by Michael J. Sullivan
Steampunk
The Bane Chronicles by Cassandra Clare (YA)
Clockwork Princess by Cassandra Clare (YA)
Lady of Devices by Shelley Adina (YA)
Prudence by Gail Carriger
The Clockwork Scarab by Colleen Gleason (YA)
The Friday Society by Adrienne Kress (YA)
Black Lung Captain by Chris Wooding
Ink and Bone by Rachel Caine (YA)
Mechanica by Betsy Cornwell (YA)
Flash Gold Chronicles by Lindsay Buroker
Rebel Mechanics by Shanna Swendson (YA)
Ink and Bone by Rachel Caine (YA)
Mechanica by Betsy Cornwell (YA)
Flash Gold Chronicles by Lindsay Buroker
Rebel Mechanics by Shanna Swendson (YA)
Science Fiction
Avalon by Mindee Arnett (YA)
Invoking Darkness by Jeanne Cavelos
Valor's Choice by Tanya Huff
The Vindico by Wesley King (YA)
Academy 7 by Anne Osterlund (YA)
Vicious by V.E. Schwab
Cassidy Jones and the Secret Formula by Elise Stokes (YA)
All Our Yesterdays by Cristen Terrill (YA)
The Comet's Curse by Dom Testa (YA)
V is for Villain by Peter Moore (YA)
Earth Girl by Janet Edwards (YA)
Timebound by Rysa Walker (YA)
Illusive by Emily Lloyd-Lones (YA)
Wearing the Cape: The Beginning by Marion G. Harmon (NA)
The Web of Titan by Dom Testa (YA)
Starbridge by A.C. Crispin
Stitching Snow by R.C. Lewis (YA)
Stars Above by Marissa Meyers (YA)
The Dark Realm by Anthea Sharp (YA)
The Comet's Curse by Dom Testa (YA)
V is for Villain by Peter Moore (YA)
Earth Girl by Janet Edwards (YA)
Timebound by Rysa Walker (YA)
Illusive by Emily Lloyd-Lones (YA)
Wearing the Cape: The Beginning by Marion G. Harmon (NA)
The Web of Titan by Dom Testa (YA)
Starbridge by A.C. Crispin
Stitching Snow by R.C. Lewis (YA)
Stars Above by Marissa Meyers (YA)
The Dark Realm by Anthea Sharp (YA)
Paranormal/Magic/Urban Fantasy
A Breath of Frost by Alyxandra Harvey (YA)
The Deep End of the Sea by Heather Lyons (NA)
Beautiful and the Cursed, The by Page Morgan (YA)
Harry Potter and the Sorcerer's Stone by J.K. Rowling (MG)
Unspoken by Sarah Rees Brennan (YA)
Unenchanted by Chanda Hahn (YA)
Libriomancer by Jim C. Hines
Unspoken by Sarah Rees Brennan (YA)
Unenchanted by Chanda Hahn (YA)
Libriomancer by Jim C. Hines
Historical
Wrapped by Jennifer Bradbury (YA)
Wild Orchid by Cameron Dokey (YA)
Heart's Blood by Juliet Marillier (YA)
River in the Sky, A by Elizabeth Peters
The Girls at the Kingfisher Club by Genevieve Valentine (NA)
A Tyranny of Petticoats by Assorted Authors (YA)
Warrior by Zoe Archer (Adult)
The Girls at the Kingfisher Club by Genevieve Valentine (NA)
A Tyranny of Petticoats by Assorted Authors (YA)
Warrior by Zoe Archer (Adult)
Contemporary
Also Known As by Robin Benway (YA)
I'd Tell You I Love You But Then I'd Have To Kill You by Ally Carter (YA)
Heist Society by Ally Carter (YA)
Heist Society by Ally Carter (YA)
Smarty Bones by Carolyn Haines
The Conspiracy of Us by Maggie Hall (YA)
Inside the Shadow City by Kristen Miller (MG)
Romance
Riveted by Meljean Brook (Adult)
Cruel Beauty by Rosamund Hodge (YA)
The Assassin's Salvation by Ruby Lionsdrake (Adult)
The Treachery of Beautiful Things by Ruth Francis Long (YA)
Kiss of Steel by Bec McMaster (Adult)
Red Rope of Fate by K.M. Shea
A Change of Fortune by Jen Turano
Full Steam Ahead by Karen Witemeyer
The Scarecrow King by Jill Myles
Beauty and the Beast by K.M. Shea
The Scarecrow King by Jill Myles
Beauty and the Beast by K.M. Shea
