Angels as main characters:
* The Fallen Series by Lauren Kate (Fallen, Torment, Passion, Rapture, and the upcoming novella, Consumed) - This series focuses on Luce, a girl who attends a boarding school for troubled teens and falls in love with a fallen angel, Daniel. It explores themes of redemption, second chances, and the complexities of love.
* The Angels series by Danielle Paige (The Angels, The Fallen, The Lost) - This series follows Lily, a young woman who discovers she's a guardian angel and must protect a boy who's destined for great things. It blends action, romance, and a touch of humor.
* The Host series by Stephanie Meyer (The Host, The Seeker, The Soul) - While this series is technically about aliens taking over human bodies, the central conflict involves a human soul fighting to reclaim her body and the spirit world. It has strong themes of love, hope, and survival.
* Wings by Aprilynne Pike (Wings, Fire, Shadow, Destiny) - This series follows Laurel, a girl who discovers she has wings and is a part of the world of angels. It explores themes of identity, finding your place, and first love.
* The Angel Experiment series by Marie Lu (The Angel Experiment, The Midnight Star, The Morning Light) - This series is set in a future where angels are treated as weapons and follows a young woman who is forced to join a war against humans. It delves into themes of manipulation, rebellion, and fighting for what you believe in.
* Angel by Margaret Weis & Tracy Hickman - This standalone novel follows a young woman who is a guardian angel and must protect her charge, a boy with a special destiny. It's a classic example of an epic fantasy featuring angels.
* The Raven Cycle by Maggie Stiefvater (The Raven Boys, The Dream Thieves, Blue Lily, Lily Blue, The Raven King) - This series features a group of boys who are searching for a magical ley line, and one of the boys, Blue, has a unique connection to angels.
Angels as secondary characters:
* The Mortal Instruments series by Cassandra Clare (City of Bones, City of Ashes, City of Glass, City of Fallen Angels, City of Lost Souls, City of Heavenly Fire) - While the series focuses on Shadowhunters, who are angel-human hybrids, angels play a significant role in the story. This series is full of action, romance, and a touch of the supernatural.
* The Infernal Devices series by Cassandra Clare (Clockwork Angel, Clockwork Prince, Clockwork Princess) - This series, set in Victorian London, features a group of Shadowhunters who are fighting against a powerful demon. It delves into themes of family, friendship, and sacrifice.
* The Beautiful Creatures series by Kami Garcia & Margaret Stohl (Beautiful Creatures, Beautiful Darkness, Beautiful Chaos, Beautiful Redemption) - This series follows Lena Duchannes, a young woman who is a descendant of witches and angels, and Ethan Wate, a human boy who falls in love with her. It explores themes of love, destiny, and the power of choice.
* The House of Night series by P.C. Cast and Kristin Cast (House of Night, Marked, Chosen, Untamed, Betrayed, Hunted, Tempted, Burned, Redeemed, Awakened) - This series follows a group of girls who are being trained as vampires and are touched by the spirit world. While angels aren't the main focus, they do appear and play a role in the story.
Beyond YA:
* The Book of Uriel by Margaret Weis & Tracy Hickman - This novel, part of the "Dragonlance Chronicles" series, tells the story of the angel Uriel and his involvement in the war between good and evil.
* The Bible - While not strictly YA, the Bible contains many stories about angels, from the archangels Michael and Gabriel to the angels who visit Abraham and Lot.
This list gives you a great start, but there are many other amazing books out there with angels as characters. I recommend checking out book reviews and summaries to find what appeals to you. Happy reading!