Tough ... I've played games with great story and crap gameplay (Blood Omen 2) and games with good gameplay but crap story (RAGE). I'd have to go for the latter. I find myself playing RAGE now and again, but Blood Omen 2 I'll watch the cinemas on Youtube since I don't have to experience the boring gameplay. But both are important though.
Playstation = The Beast from the East
Sony + Nintendo = WIN! PS3 + PSV + PS4 + Wii U + 3DS