6. Dark Souls
Dark Souls is such a strange beast, it's verging on David Lynchian levels of fan adoration, where if you've broken through the obscurity-barrier what awaits on the other side is a title you'll be screaming from the rooftops about for years to come. Whereas to the rest of the mass gaming populace it looks about as inviting as tucking into a leathery shoe for supper. The fascination of the 'Souls series is specifically because of this level of ambiguousness that forces the player to provide their own take on the mythos, but more so for this instalment in particular it has one of the best world designs in modern gaming. By connecting a series of rooms, corridors, stairwells and other thematically different areas - like swamps, cathedrals, underground caves etc. - you're forever on your toes pushing forward, only to discover a lesser-travelled route doubles you back to somewhere you thought you'd left far behind. It's astonishing every time, and if you can get on board with the harsh brutality of the enemy design and the big ask on behalf of the player to conquer what's ahead with minimal checkpointing, doing so in such an expertly designed game is one of the most rewarding experiences you'll ever have.