What books should i read for my Juniors' thesis?

So i'm a junior in high school and we have to do this thing in English called a junior's thesis. Basically, we find three books (or two books and a movie) with a central theme/idea/motif etc. and write a 10-12 page essay on it. I'm having a hard time finding these three books with a central theme. The problem is that these books have to be approved by my teacher so it has to do with lterature (so i can't write about Harry Potter and Twilight, although that would be awesome lol). I'm thinking about using The Great Gatsby as one of my books, but i don't know what else to read that would have themes or motifs similar to that in The Great Gatsby. HELP!