You can never go back. Or can you?
It's a defining characteristic of this generation that most of the games in our list play differently now than they did at launch. Bugs have been fixed, classes rebalanced, level caps raised, new content and modes added. The internet has even reached into solo experiences like Bethesda's RPGs and synced them with the remorseless march of time. If such a thing as final cut ever existed in video games, it's gone now. You can still experience most of the original versions if you try, but you'll have to try: wipe that install, delete that save data, unplug the router.
For World of Warcraft, though, that's all but impossible. Blizzard's mighty online world is now almost unrecognisable as the game that, just before the new consoles launched, heralded the dawn of a new age - the age, in the term coined by Valve's Gabe Newell and parroted by an army of publishing executives, of "games as a service". Not only has WOW undergone constant evolution in mechanics, design and philosophy over the last nine years, but its original content is gone. Wiped from the servers, never to return.
It was swept away by the broom of 2010's Cataclysm expansion, which exhaustively redesigned two continents' worth of dungeons and questing, in many places from scratch. This is a game that now contains nostalgic references to an earlier version of itself. Cataclysm was unpopular with WOW players - mostly for other reasons to do with its endgame - but it still might be the single most extraordinary thing I've seen a games developer do in my decade or so writing about games.