A lot of Kings output since he came back from his accident has ranged from very bad to meh personally. I really do love the ending of The Dark Tower though. Honestly his best book this century for me was Revival, doesn't tie into DT, but it I think it has a similar tone.
I would agree with this, but 11/22/63 was just as awe inspiring as some of his more lauded older works. Just absolutely incredible.
"It" is just really good, and not a bad idea to get through it before the new movie hits. The Stand is also really wonderful. The others are always going to be kind of hit or miss. I was iffy reading the Dome, and the ending made me never want to remember the book again. You'll find endings in general is something King has somewhat of a problem with.
Dark Tower series is really solid as well though. 1st is the weakest book in the series, and that says a lot since it's still a good read. I found 4 to be pretty boring, but apparently I'm in the minority with that. 2 is probably my favorite of the series, though 5 is up there with me.
Considering the import, I really should probably get to Insomnia sometime. Maybe that's what I'll use some of the audible credits I've been hoarding on.