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.
Final Fantasy VII was my first RPG. It had a good (but sometimes difficult to follow) story, lots of quirky characters, Full Motion Video sequences, and a musical score that nears perfection. Hearing those songs today doesn’t just remind me of the game, it brings me back to all the emotional moments in the story where I felt like I was actually there, feeling what those characters felt and being there fighting along beside them.
A lot of how I feel about that game may be related to the fact that I was a teenager when I experienced it, but the lasting impression of that experience is why I think it is one of the greatest games of all time.