I think all the best ones which really capture the feel of SK well are those by Frank Darabont. The Mist, The Green Mile and Shawshank are all excellent.
I really don't like Kubrick's version of The Shining. It's reasonably entertaining if you pretend it's not a SK adaptation but it compeltely missed the point of the book and reduced everyone to the most one dimensional version of the characters possible, especially Wendy.
I do like 1408, it's a lot of fun and it pleases me no end that the hour long countdown passes almost in real time 
I've also got a real soft spot for some of the rather cheesy made for TV films. There's a version of The Shining which for me is a much better adaptation than Kubrick's even though it suffers from dodgy effects and daytime TV acting in places (apart from Steven Weber who is brilliant as Jack Torrance). I also enjoy IT (mostly for Tim Curry!!) and The Langoliers.
It's not an adaptation of his own work but I did really enjoy the TV series Kingdom Hospital which SK was heavily involved in. I also enjoyed Rose Red which he wrote specifically for TV.
11.22.63 was excellent and I've just started watching the new TV series of The Mist which is pretty interesting so far. DH very much enjoyed Under the Dome, at least the first seasons or so, and I really liked the book so that's on my list of stuff to watch.
I've just seen there's a TV adaptation in the works of Wizard and Glass which (despite the fact it's my least favourite DT book) I'm actually far more interested in than the DT film.