If you haven’t yet, try Subnautica. For anyone who hasn’t heard about it, it’s an underwater open-world exploration/crafting game. The 3D exploration is something you don’t usually get in other open-world games.

The Dark Souls series, Halo and especially Destiny. Bungie has an incredible ability to create immersive skyboxes imo.

STALKER SOC and COP are incredibly immersive, especially when just exploring around and looking to make a little side money. The world is so apathetic to your existence. It’s terrifying how fragile you are. Going through the woods and hearing or thinking you hear the sound of some mutant is paranoia inducing.

Multiplayer, but Rising Storm 2: Vietnam has had some hugely immersive moments especially with active commanders and squad leader chatting. One of my most vivid memories is attempting to assault a Vietnamese position but our commander had mistakenly calling in napalm too close and ended up taking out our own side. I just barely escaped the flames but saw many other troops die with NPCs screams. Over the chat somebody brilliantly recited, “That fucked up fire mission got a lot of good men killed, sir.” Perfect.

• Subnautica - If you want to be immersed in a sandbox ocean environment with horrible sea creatures
• Elite Dangerous - Beautiful sound design and an immersive spaceship cockpit point of view within a 1:1 scale Milky Way

Cyberpunk 2077 is definitely up there. Half life Alyx as well, but it’s VR so kinda comes with the territory haha.

I’d add the Zelda games too, especially TOTK. They’re not quite as immersive but TOTK has a great focus on fun and creativity, although the balancing drops off badly in the mid-late game as the late-game armour upgrades are really OP.

Then there’s System Shock, Prey, Bioshock, etc. even Alien: Isolation to some extent, but I don’t like those games that never give you time to rest and do some non-combat stuff.

Squad is the most immersive multiplayer shooter I’ve ever played. Can’t recommend it enough. Amazing community, people are always on mic.

Hellish Quart is i fighting game heavily inspired by hema (historical European martial arts). The different fighting styles of the characters are all inspired from old manuscripts and stuff. It’s great and you can play it on steam remote play together so you only need one person to have it to play with friends.