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.
Original x-com was great you had lots of research to do, bases to set up with defenses, manufacturing, storage, radars etc. Could make money from both loot and manufacturing your own products.
Then there was intercepting UFOs with your fighters followed by the actual missions were you could use all your researched gear, get loot, capture Aliens to interrogate for more research and level up your soldiers.
I still play the openxcom version now and again with various mods but yeah as a kid I used to play the original on the original PlayStation with its mouse and it’s without a doubt the game I’ve probably spent more time on than any other.
Wasn’t a huge fan of the remade ones to me the original is the best one.