Two initially jump to mind for me.
Outer Wilds took me three attempts to get into, but when it did…wow. Its a game that I is definitely more than the sum of it’s parts, and one that I’d argue is genuinely beautiful in it’s story and how it tells that story.
That said, once you’ve worked out the games mystery; it’s story, it’s tricks, timing and logistics, I wonder how more pull the game would have.
Return of the Obra Dinn is a game that I spend a lot of my time thinking about. The music, the atmosphere and of course, the games moment to moment gameplay.
Those puzzles will likely (hopefully) melt from my mind at some point, but even then I fear that initial sense of excitement and intrigue will be lost.
As much as I plan on going back to it at some point, I’m not sure a game of it’s nature is all that well suited to additional playthroughs unfortunately.
Mass Effect trilogy. Bioshock. Deus Ex (the first game). Disco Elysium: this game made me laugh so hard I ended up crying, made me feel the entire rainbow of emotions. Wish I could experience that again). The Witcher 3.
But yeah, most of all Mass Effect. Still look forward to N7 day each year, but I would give up my entire Steam library to experience the trilogy for the first time again.