John Scalzi is maybe the best science fiction writer alive in my humble opinion. His Old Man’s War trilogy is one of my absolute favorites.
His Military science fiction reminds me of Heinlein in style if not ideology. John’s characters often observe society and grows in insight and ability as the story gets along. Stylewise he is witty and pointed and have a sneaky kind of humor that hits you from behind at times. Ideawise he is original, surprising and ironic, a great worldbuilder.