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 think of CDDA as mostly Dwarf Fortress with vehicles. Just as complex in the combat, but not as complex in world gen or with civilizations (because zombies who cares lol), but the vehicle building and sim is as far as I would expect DF to have, if it had vehicles.
I once made a giant mobile fortress that could just drive straight through most anything that wasn’t made of metal.
Hells yeah; I’m on a boat kick right now and it’s been super fun. Both games are fantastic.