A second vote for---
Chaos Isaac said:
Most games with stories would be nice to experience without knowing what's going to happen (KotOR, BioShock, The Walking Dead S1), but Dark Souls was a masterpiece work of art that got under your skin, that unfolded, that had to be explored and thought about and assimilated for weeks and months. Its lore, themes, and intangibly tangible atmosphere/'feel' made for something unique, experientially.
No game's ever felt as rewarding to get better at, and to become accustomed to its world, mechanics, and sense of place. It can absolutely be enjoyed again, but obviously never in the same way.
Then again it'd have been nice to play
Spec Ops The Line completely unaware of a certain key moment. As it turned out, what many saw as the main spoiler/reveal
wasn't by any means the biggest or most important, so the story and experience still utterly sideswiped me.
Red Dead Redemption would be nice to play anew; the best writing Rockstar ever put out, with a beautiful, intelligently nuanced story and a stunningly crafted world to explore. There was a beauty and pathos to that game that was startling on a first play; a simple song at a certain moment was completely unexpected, but seemed headily perfect.