Try adventure novels (which is what I'd suggest for much of high school reading). Horatio Hornblower, Captain Blood (Rafael Sabatini), Kipling, Stevenson, etc. Try G.A. Henty, one of the most popular novelists of the turn of the century (20th century, that is), making a comeback among Christian homeschoolers.
Try "The Saint" detective stories. You need a top quality vocabulary and a knowledge of history, Latin quotes, French and German, and comparative religion to get through this stuff with full comprehension. Dang it, people used to be somewhat educated! "The Saint" is pulp magazine fiction, for heaven's sake, but the author assumed the reader knew French and German!
There is plenty of good, solid, classic fiction that is oriented toward the teen/young adult perspective. And let's be honest, adults love this stuff too. It wasn't teenagers buying the World's Great Pirate Novels in the 19th and 20th century, it was adults. It wasn't teenagers who made Louis L'Amour one of the bestselling novelists in history.
I dug the Harry Potter books, once I picked them up. (The hand of God placed one in the bathroom when I was up at 2 a.m. with Vlad, some months back.) Of course I bring a middle-aged-mom perspective to the stories. Want to hear my thesis on the essential theme of fatherlessness in the Harry Potter series?
I like Henty for what he is (boys' books that are a little heavy handed in the dialogue but lots of history and action); another similar writer that is very pleasant to read is Horatio Alger -- and although I don't care for Westerns as a general rule L'Amour is the best, except for Owen Wister.
Interesting sidelight to the Harry Potter stories. I may approach them from a slightly different angle, because I am a big fan of British children's literature.
From the point of view of someone who has read the "Jennings" series, the "Chalet School" series, "Stalky & Co.," and other British school stories, Harry Potter is essentially the British public school story with a little magical window-dressing.
The same themes recur . . . the idea of sending your kids off from the age of 8 to boarding school is pretty wild to Americans. Even Kipling saw the danger in it . . . especially the children who were sent from India back to England (as he was). He mentioned with some disgust in his autobiography a boy who became a snob in public school, and dismissed his mother as "not quite our type, donchaknow . . . "