Under The Dome and IT are two of my favorite books of all time. Under The Dome is criminally underrated, it's absolutely brilliant, a true masterpiece. Some of his best characters, and in MY opinion, his best ending.
IT, meanwhile, is the most terrifying book I've ever read, one of only a few stories where dual timeframe actually works, and also has an amazing final act.
The Shining, Salem's Lot, Dolores Claiborne ("Sometimes, being a BITCH is all a woman has to hold onto."), Misery, The Long Walk, and The Running Man were also all amazing.
I personally hated The Stand, I thought it was long and boring with cardboard characters and one of the worst deus ex machina endings of all time. And I couldn't finish The Tommyknockers or Insomnia cuz they were so boring.
The Dark Tower series is so ****ing long and a collaborative effort, but really great.
Hearts In Atlantis was probably the only story I couldn't finish, and this thread just reminded me to read its Wikipedia page. It was good, just not my cup of tea. It really lacked the fantasy/horror aspect and was more about Vietnam-era America.