I read a lot (most) King voraciously for a long long time. I found I really enjoyed the way a lot of them were interrelated, particularly (maybe almost exclusively) the Dark Tower tie ins - for me, there were many "a-ha" moments where characters or concepts return (Everything's Eventual is a great example).

There's this obsessive sort of branching that gives me the feeling the DT story has been gnawing at his consciousness just about forever.

With that in mind, the short works feel more like a pressure relief valve.

"Yes, yes, yes DT, my master, my muse, I will write more about you soon, but let me scratch a couple itches and take a breath once in a while, 'kay?"

(PS - Needful Things is great, and a lot of it is short-storyish feeling, as the individual characters' backstories are sketched out)