I agree that the best games can combine good writing with good systems, although if forced to choose I think I will always lean toward systems, because narrative tends to be less interactive (except for a choose-your-own adventure element) and I have books and movies for that. Specifically with RPGs, the backstory/lore/overall ‘world vibe’ is usually more important to me than quality of dialogue, characterization, plot development, etc. I cut Elder Scrolls a lot of slack in that respect.