I'm a school librarian and this is what I've had requests for and what has been recommended. First I have a URL for you to the American Librarians Association website. It is a great place for teen reads, especially reluctant readers:
(Or go to [url="http://www.ala.com"]www.ala.com[/url] Click on Libraries & You, then Best Books for Young Adults)
Some of the popular authors with my teens are:
Walter Dean Meyers (Scorpion, Monster) He writes about contemporary issues and urban youth
Nancy Farmer (House of the Scorpion, Sea of Trolls, A Girl Named Disaster) She write Science Fiction/Fantasy but very well
E.L. Konigsburg - She writes contemporary issues, relationships, and family type stories
Sharon Creech (Chasing Redbird, Love That Dog) - She writes contemporary issues, relationships, and family type stories.
Francesa Lia Block (these can be a little racy, but with an open minded teacher are great for starting discussions about contemporary issues)
Louis Sachar (Holes) He may seem young but for reluctant readers or lower ability readers he has great potential.
Jerry Spinelli (a personal favorite; Stargirl, Loser, Maniac Magee) - His books often address issues like racism, acceptance, individuality versus "fitting in". He is also great for reluctant readers.
A great graphic novel (yes they are novels I am converted to their literary worth) is the series Sandman by Neil Gaiman. Students will need to research mythology, classic literature, and common folktales to truly understand the nuances of these novels. However, I recommend it only if your department is feeling adventurous.
I could go on, but this post would be way too long. I hope these help!