Here be spoilers, I guess.
I tend to play story-based games – I enjoy the interaction with narrative, but I’m also aware that the narrative is, to one extent or another, already locked into a particular course. It may be the Final Fantasy form which will in effect be a series of pretty cut scenes interspersed with your pressing X every few whenevers, it may be Mass Effect, wherein your choices can affect what characters live, die, stick around and leave – either way, the plotline will have been anticipated, put in place and you will be constricted by the world of the game.
Turn my brain off 