One of the top YA fiction books is 'City of Bones' from 'The Mortal Instruments' series by Cassandra Clare. It has a great mix of fantasy elements like demons and shadowhunters. 'A Wrinkle in Time' by Madeleine L'Engle is a classic. It takes readers on a journey through time and space. Also, 'Looking for Alaska' by John Green is a beautifully written book about friendship and loss.
Definitely consider 'Red Queen' by Victoria Aveyard. It has a unique world where people are divided by blood color and there's a lot of political intrigue. 'Simon vs. the Homo Sapiens Agenda' by Becky Albertalli is a wonderful coming - of - age story about a gay teenager. 'The Book Thief' by Markus Zusak, while not strictly YA, is often read and loved by young adults. It's set during World War II and told from the perspective of Death.