Definitely 'A Court of Thorns and Roses' series by Sarah J. Maas. It has a great blend of fantasy and romance that is very appealing to teens. The main character, Feyre, has a complex relationship with Tamlin and later Rhysand that is full of passion and growth. Another is 'Dumplin'' by Julie Murphy. While it's more about self - acceptance, there is a sweet romance in it as well. And 'Six of Crows' by Leigh Bardugo also has some great romantic sub - plots among its main adventure story that teens love.
Some popular gay romance novels for teens in ebook format are 'Heartstopper' by Alice Oseman. It's a graphic novel series that follows the sweet relationship between Charlie and Nick. It has been praised for its positive representation of queer youth. 'More Happy Than Not' by Adam Silvera is also a great choice. It delves into the life of a teen named Aaron who is dealing with his own identity and feelings. Then there's 'Boy Meets Boy' by David Levithan, which is set in a world where being gay is completely normal and accepted, and it tells a lovely story of love and friendship among the teens.
The 'Harry Potter' series by J.K. Rowling is also great for teens. It's a magical world full of adventure, friendship, and the battle between good and evil. Teens can get lost in the Hogwarts School of Witchcraft and Wizardry and follow Harry's journey as he grows up.
A really good one is 'Anne of Green Gables' by L.M. Montgomery. It tells the story of an orphan girl, Anne Shirley, who has a vivid imagination and a big heart. Her adventures and her relationships with the people in Avonlea are both heartwarming and inspiring for teens.
I'd recommend 'To Kill a Mockingbird'. It offers important life lessons and insights into social issues. The story is both touching and thought-provoking for teenagers.
Barnes & Noble could be a good choice. They have a dedicated section for teen novels and provide various editions and formats. Also, their website is user-friendly and has helpful reviews.
Another option is 'The Outsiders'. This novel explores the differences between social classes and the power of friendship among teenagers. It's a short but impactful read that can make FL teens think about how they view and interact with others.