Mine is probably Sekiro. I really dislike the story being about feudal Japan and the main character being the grunt for a privileged asshole but the combat and bosses are so good. I don’t think any game will ever top that.
To see how good the game is, compare it to J*di Knight: Fallen Order, which is essentially meant to be a clone of Sekiro but is so lacklustre in comparison.
I pirated Fallout 2 last year just for fun, but it was just unplayable for me coming from the newer ones. The series is really fantastic though, did you enjoy NV, 3, and 4?
3 and New Vegas I never really got more than a few hours into, mostly due to crashes and corrupted saves. New Vegas I would like to get back around to at some point though, I love deserts. 4 is okay but hasn’t grabbed me either. The weird thing is, nostalgia isn’t at play here. I first played Fallout 1 in 2016.