I prefer All the Pretty Horses to Blood Meridian and these are the only two McCarthy works I have read to date.
All the Pretty Horses presents a more fluid narrative where Blood Meridian, though it does offer more impressive writing on the whole, ends up being very episodic and offers very little satisfaction when it comes to story.
All the Pretty Horses could be used in high school classrooms (I would use it in conjunction with Ernest Hemingway in exploring the "modern" hero and/or the isolated hero.).
McCarthy's strength in the classroom probably most clearly comes in the relationships his work has to the work of 19th and 20th century writers. I don't think that McCarthy is especially expressive of literary style in an original way however, but, then again, maybe I just haven't read enough of his work.
I really liked The Road, but I also have a love of good science fiction. The Road has some of both--it's a well written book with good characters, and a plausible scenario of what could happen after an out of control war. It manages to explore basic human relationships under extreme conditions in a way that rings true. For teenagers, I would think it would provoke some thought about what they would do under similar circumstances, but might be better for a book club.
I have yet to read Blood Meridian, but it's on my list. I personally like the Border Trilogy--my favorite is All the Pretty Horses. I really like the development of character in the novel and the journey that the characters take in Mexico and then back home. Plus, I like McCarthy's description of setting and scene which is a hallmark of his writing overall. I do teach sections of The Crossing for this purpose (a scene from the novel appeared on the AP lit test some years ago), but overall, I do think McCarthy's work is overlooked in high schools for the reasons mentioned above regarding violence, and the fact that his writing style is rather sophisticated. Also, I think that McCarthy's penchance for writing about "journeys" of some sort is beyond an average teenager's experience.
Wow, that's really hard. I guess I'd have to vote for Blood Meridian also, though there are some of his novels I still have to read. The imagery in that book is astounding, and I use an excerpt for my US History class to describe the intensity of the Indian wars on the frontier and in the Southwest especially.
A little partial to No Country for Old Men, but only because my brother was in the movie. Blood Meridian still beats it out in my opinion.
My favorite McCarthy novel is Blood Meridian. Although most critics find considerable trouble with the historic accuracy of the novel, I find it to be a fascinating glimpse (even if fictional) into the concept of growing up in the Old West.
I do believe McCarthy is overlooked at the high school level for a variety of reasons. The violence throughout his works is strong enough to keep many teachers from teaching it--a kind of self-censorship to avoid disapproving parents or administrators. McCarthy's unconventional style, I think, also turns off some teachers as using his novels as model texts.
I'm a big fan of The Road, but I do not think that it gets overlooked in high school, I believe that some of the scenes are too graphic for high school and the main themes and messages may be obtained from other dystopia novels, such as Brave New World or 1984. All of these novels demonstrate how society destroys itself, but The Road's grotesque approach, such as the spit-fire newborn, and general cannibalism, may be too much for a high school classroom. My students are often distraught over John the Savage's end, and Winston Smith's end, I cannot imagine how they would feel to see the father's end.