my favorite game genre- is RPG fantasy. in articular an isometric view world exploration is what holds my interest. In particular, a game that is fluid in its story line is important, even a doom like FPSG is in my tops list if there is a story or underlying world to negotiate.
Descent
Universal Paperclips
Deuteros
Infestation
Archipelagos
Quadralien
Populous II
StarCraft
Dungeon Master
right now Overwatch easily wins out for taking my time but if youre thinking more all time greatest i like to think of the likes of Chrono Trigger, Nier Automata or FFVII
all depends on what you want from a game really, however i suggest if you fancy an existential crisis backed up by a solid combat system and a divine musical score then i couldnt more strongly suggest Nier Automata, it is in my opinion the strongest argument for video games as an art form in the last decade, just be sure to switch it to original language as the dub is abysmal