Alright, after a lot of recommendations from friends and DTFers alike, I'm starting The Dark Tower series.
The Gunslinger by Stephen King
As the others have already said, don't judge the series by the first book. I almost gave up when I first read the Gunslinger, but it's the second book The Drawing Of The Three where everything starts to get real great.
I bought the whole boxset with all the seven books plus Wind Through the Keyhole (or whatever it's called, my bookshelf is a bit away from my PC so I don't want to get up and check it), so I suppose I won't stop after the first book. Good to see the positive thoughts on the series, though.
Dead Beat by Jim Butcher.
Don't look at me like that. I can stop wherever i want.
I kinda don't remember what happens in these books between Summer Knight and newer books—well, I remember
what happens, but I don't remember what happens in which book—but my advise would be to keep at it and just continue reading book after book, not stopping somewhere in the middle of the series. That's what I did and I loved the experience (really, I just couldn't put them down because I loved them so much).
However, it's up to you. While a lot of these books are kinda the same in terms of structure and narrative, the things really get more wild later and I suppose you may find yourself surprised at the turns of events as these books progress.