I have a good opinion of The Road. I think some of the literati who go ape for Blood Meridian were a little hard on it, or at least too jaded. McCarthy stoked that fire a bit himself, though. He is notoriously reclusive and has made himself less than accessible to the Powers That Be over the years. But (a little hilariously) he made a point of "doing Oprah" when The Road came out, to promote his book to be sure, but also to just diss 'em. I kind of like that.
Spoiler alert: If you don't want to know how The Road ends, skip the next three paragraphs. Skip the paragraph after that if you've never read or seen World War Z, and the one after that if you've never read or seen No Country for Old Men.
I saw the man with the crossbow, who the boy goes off with at the end, as the Christ figure (crossbow, get it? And it's on his back). The boy and his father are just "carrying the fire," which has to do with the Valentinian gnostic concept about redemptive purity. Or you could skip the hocus pocus and just say that they maintain their humanity because they will starve before they join the "zombies." The father fulfills his duty by delivering the boy safely to an area where a community of like-minded people can find him--perhaps.
I would have ended the story differently. The sudden appearance of the Savior figure was too much of a deus ex machina for me (where were the "good guys" all through the rest of the book?) I would have made it more ambiguous. The father would have been teaching his son mushroom lore (or mycology, if that's the word) as they passed through the dark mountains: remember this kind because you can eat it; remember that kind because, if you ever really needed to die, it would do the trick; avoid this kind because it will make you go crazy and see things for a while. But the boy would have a hard time remembering the differences, and eventually his father would tell him to forget it. After his father dies, I would have shown the boy sitting beside his body eating a mushroom (the pistol would be out of bullets, which it is not in the book). Is he eating to live? In other words, left alone in the nightmare world, has he now taken responsibility for his own survival (by choosing the right mushroom this time)? Or with his father gone, has he chosen to die? And was he even capable of choosing the right mushroom? Was it one of the hallucinogenic ones?
At that point, after the boy had sat beside his father's corpse for some time, the man with the crossbow on his back would arrive. Is he what he claims to be? Or is he just a cannibal trying to con the boy out of the pistol, then lead him away be slaughtered and eaten? (That point is actually left slightly ambiguous in the book as it is--and to good effect, in my opinion). Or is the man Jesus, come to take the boy to be with his his father--in other words, is the boy dead, too? All that would be ambiguous in my ending, and made the more so by the potential that the boy's perception might be clouded by hallucinations.
I never saw The Walking Dead, by the way, but it does seem a little similar to The Road in some ways. (I watched World War Z on the back of a plane seat recently and was disappointed that at least one of Brad Pitt's little girls didn't get eaten up--but I guess that's what sequels are for. )
I had the very strange experience of finishing No Country for Old Men on an airplane, and then watching the movie on the back of the seat in front of me. Consequently, I have a little trouble sorting them out in my memory. They both (I think) had a Ford Madox Ford-style modernist ending, in which the climax happens "offstage." That was fine in the book (I think), but later I heard a lot of disappointed movie-goers say that they felt like they had missed a step on a staircase. People also complained that there was no reason for the wife to have been killed, too. But personally, I thought that was one of the more powerful moments in the book. The devil goes by karma, not mercy.
Or the Glanton party's helicopter crashes and "the boys" have to fight their way out of Mexico while the UN just shrugs? Or the Judge is a secretly a Roman general who will have his vengeance--in this life or the next? (Actually that does sound a little like the Judge).