There's a reason why I am re-reading the Dark Tower series. It's hands down one of my favorites though the last few books break my heart because IMHO King needed to reign himself in a lot. Let's not talk about the world's most copped out ending ever that still has fans mad to this day.
So far through my re-read I am up to book #4, hope to knock a few more of these out for this year's bingo.
I think the reason why this is still my favorite is that you have this group of people who end up doing what they can to put the world they know of it and other worlds to right. They love each other, are willing to die for each other, and in the end they will all do what they can to get to the Tower. King plays with a lot of fantasy elements inspired from King Arthur, grimm's fairy tales, and of course his own works. There are a lot of Easter eggs for King's Constant Readers which also makes this series fun.
I do not aim with my hand. He who aims with his hand has forgotten the face of his father. I aim with my eye.
I do not shoot with my hand. He who shoots with his hand has forgotten the face of his father. I shoot with my mind.
I do not kill with my gun. He who kills with his gun has forgotten the face of his father. I kill with my heart.