You can truly use any book with DITHR, so it's up to you what books to choose. High school level literature is a very broad category, so you can truly go any way you desire. We are still in the midst of previewing appropriate high school material to meet our own family goals, but I can list a few you could consider to get you started.
This year my son is reading Pride and Prejudice (and if you get a chance to watch the BBC's Pride and Prejudice DVD series with Colin Firth as Mr. Darcy along with the readings, it is wonderful.). I'd put this under realistic fiction or historical fiction.
My son truly enjoyed it.
We have also done The Importance of Being Earnest (which is a play that has a DVD movie with Colin Firth in it as "Earnest/Jack"). The DVD is a bit lovey/dovey in a few parts, so you'd have to determine if it suits your son. I would put this under humor, but you'll need another title to use for this genre as "Earnest" is short. You could possibly use Jane Austen's Emma to fill this out, as it is humorous and quite witty in many ways. (Emma also has wonderful DVD's that tell this story either with Gwyneth Paltrow in the lead or Kate Beckinsale stars in an Emma as well.)
Mama's Bank Account would be another good humorous title that would fit here.
My son is also doing Silas Marner, which I'd put under realistic or historical fiction. Wonderful book!
We are doing The Scarlet Pimpernel (which is definitely historical fiction, or it could also fit in adventure or possibly squeeze into mystery if desired).
Animal Farm is another short play that could fit under fantasy. We will do this one as well. You could possibly consider Gulliver's Travels for the rest of the fantasy genre, depending on how you feel about that particular title. We are still weighing it.
The Vicar of Wakefield is another good title with real possiblities. It is well-written and has good moral lessons and could fit under realistic or historical fiction. It does not flow quite as easily as a Jane Austen title, but is still very good.
For adventure, you could also consider either Twain's Prince and the Pauper or Robinson Crusoe. My son has read Robinson Crusoe already and will be doing Prince and the Pauper this year.
The Old Man and the Sea is another good adventure. Ivanhoe is another good adventure title that my son really enjoyed, and it could also fall under historical fiction too. It is longer but not such difficult reading.
A short Shakespeare play would be worth considering, such as Much Ado About Nothing or The Taming of the Shrew possibly, or any of Shakespeare's shorter plays that you are comfortable doing.
Sometimes Shakespeare's use of language or the remarks or slurs he uses can be a barrier, depending on how you feel about some of that.
For biography, you could consider Up from Slavery by Booker T. Washington, or The Autobiography of Benjamin Franklin, or if you want a lighter read Invincible Louisa by Cornelia Meigs (about Louisa May Alcott), or Abigail Adams by Natalie Bober, or The Story of My Life by Helen Keller.
For nonfiction, you could use any of David Mccullough's titles. 1776 would be one option, although it is long. Mccullough's Truman, John Adams, and Mornings on Horseback would all work under biography too. Mornings on Horseback is the shortest.
Progeny Press has a very good poetry guide that you could use to study poetry for a portion of the year as well. Typically, a high school level literature study will include a combination of poetry, short stories/plays, and full-length novels.
Anyway, just a few ideas to get you started. As we write our guide for geography, we will be utilizing some of these titles above for the literature portion. Should the Lord use us to write future high school guides, we would likely also be scheduling some of the titles above in future guides as well.