A Song of Ice and Fire.
I enjoyed the first 3 books, then I hit book 4 and I was done. Several of my friends are huge fans of the show; I watched the first episode and couldn't bring myself to care.
It's weird: I have a peculiar tolerance for certain things. If a particular line is crossed with me, it's like flipping a switch. I go from being a fan to having no interest whatsoever. The last season of BSG did that for me as well, and the finale was just the icing on the cake. I couldn't bring myself to get into Caprica, and whatever thing they've cooked up next doesn't interest me at all.
I think what it is is that I have no tolerance for drama for the sake of drama. Characters acting inconsistently or just killing somebody off solely for the controversy annoys the shit out of me. Martin's Song of Fire and Ice has developed that feeling, although he fooled me a bit at first. The Walking Dead (the show, never read the comics) has also done that for me.
Funny, it was the same with me. I was really into it at the start, I just grew more and more disillusioned with it until I felt like I was forcing myself to continue and just decided that I didn't have to keep reading. I'm attracted to well written epic fantasies, I can even accept mediocre fair when I'm in the mood. There's just something about ASOIAF which simply kills the appeal to me -- to the point that Kafka felt like an uplifting change. Perhaps it's the characters, most of which I didn't care for. Maybe I just felt the grimdarkness grating after a while. I think I might have just run into critical point with sprawling narratives that feel like they aren't going anywhere that I couldn't take anymore of it.
I don't know if I want to see Game of Thrones, I hear ravings of fans and friends imploring me to watch. I simply doubt I'll like it. Usually I like the fictional source material and am disappointed with its dramatic adaptation. I've never encountered the reverse.
The Walking Dead comic is excellent, as is the game series. I haven't caught up on the show yet.
Caprica was pretty banal, outside of the intriguing setting.