I think the common denominator is a strong / immersive story and universe that appeals to me (big fan of sf), interesting mechanics and gameplay in a way that makes the game unique in its own way, and the artistic approach behind the game, so for each of those :

• Outer Wilds was a fantastic experience that you can only live once, the freedom of exploration is crazy, the feelings you can go through in the span of a single minute make it so memorable, I connected with this game like no other
• Death Stranding I played during one of the lockdowns, and after hiking in Iceland, it was a continuity of these two experiences that felt very personal. It was also my introduction to Kojima games. I found it to be such a premium experience and statement about video games, I loved the insanity of the plot, and once you dug deeper, you find all the artistic inspiration and process that went behind the game, it’s an insane work of interactive art
• Disco Elysium I was already fully on board just learning about the game, I sympathise with the authors, the fact that it started as an rpg campaign, with immense lore behind it, love the art style, the narration, the story and its themes, I haven’t lived in post USSR Europe but the game make me nostalgic/melancholic for a time, aesthetic, struggles I didn’t know

They’re my absolute favourite but some games come close, Inscryption, Pyre, Spiritfarer…