Duma Key and 11/22/63 remain close behind. I'm not into his newer books mainly because I don't enjoy it when authors insert their own strong political or religious beliefs into their fiction, even if I agree with it. I read to
escape the political and religious battles (and no, I absolutely don't begrudge an author for doing so; it's simply not my cup of tea). I am somewhat more tolerant to parables, parallels or satire like Gulliver's Travels, etc. Again, and I cannot stress this enough, this is a "me" thing; authors and other readers can, and should, do what they like <g>.
I need to check out The Long Walk some time.