Any good books similar to the style and themes of Aldous Huxley's novels?

He’s my favorite author right now. I’ve read Brave New World and, just recently, Island (his last book, and what he considers to be his best). I’ve read other books similar to his style and genre of writing: Orwell’s 1984, Bradbury’s Fahrenheit 451, and Lois Lowry’s The Giver was my favorite book when I was growing up.

I’m looking for some good books to read for the rest of summer, so any good suggestions would be great. (I’m a Lit major, so don’t worry about dishing out anything too challenging for me to read.)