It's so hard to pick between Skyrim, Red Dead Redemption 2, and the original Final Fantasy VII!
I play RDR2 so much. It's a beautiful game, the character/horse animations are out of this world, the details in the world/animals/people are incredible, and it's the most immersive game I've played. The story was also pretty good, but the takeaway really is the attention to detail and the huge world. Best present my bf could've bought me tbh.
Skyrim reminds me so much of RDR2 in the open world aspect, but I love it as a role playing simulator and an inspiration for my own writing. I've modded mine to the point it's not even Skyrim anymore lol, but the base premise of the game still is good. The OST is beautiful too.
FFVII has the best story in a game I've played so far. Without going into spoiler land, it really was the first game to make me think about characters, their stories, and how the world is woven in with them. It almost played like a mystery novel to me, and was very very enjoyable despite how sad it was. I haven't been able to find a game that has been as well written as that one and got me as invested in it.