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.
You’re basically dropped into a huge set of mysteries.
You get to explore, at your leisure, anything you want.
There’s places and dialog and written records that contain clues and references to different threads of those interconnected mysteries.
As you play, read, explore you uncover more and more and what happened, is happening, and will happen start to make sense and you build a picture in your mind of what’s going on.
There’s no unlocks or progress except for these moments of discovery. And as you learn and discover more you can get access to new places to dig into the mystery because you have acquired the knowledge that lets you do it.