I'll be honest, I am ripping this topic straight from the Waypoint forums, but I thought it was a nice simple enough one.
I think one obvious answer here is Dark Souls. I played through Demon Souls, and enjoyed it, but I just can't bring myself to play a game like that again, as much as I hear great things about it. Persona is another series that I have mentioned before, I have tried to go back multiple times, but just can't bring myself to care enough to continue.
What are some games, franchises, even genres, that you wish you were able to stick with, but just can't find it in you?