Rules: just pick 1 and explain why.
I’ve been playing since the NES and despite being from a low income family I had the luck of being able to play and own many consoles over the 3 decades of my life, plus some pc.
If you ask me right now? Resident Evil 4 (2005).
A before and after in gaming, to this day still extremely fun to play even for casuals but 20 years ago it was THE masterpiece. And everyone took notice of it, everyone played it, even players that didn’t cared about resident evil. The gameplay was so good that it got photocopied by everyone right after in the action genre.
Arguably the last big innovator in videogames minus Minecraft and… PUBG (Fortnite did it better I know).
Try to NOT pick your favourite game, that’s a different thing.
I read somewhere that back then Microsoft was looking to buy some game to include on windows and everybody was showing then games that are more “videogame-ish”, with some level of violence or stuff like that, which Microsoft didn’t want. Eventually some guy at Microsoft had just rejected another game and said something like: “can’t someone just create a pinball game or something?” and someone overheard and created what we now know as Space Cadet Pinball.