TotK less ****ing rain.

Stardew Valley is pretty much perfect as is, and I've still never even used mods on it yet.
But if I could add stuff
-Zuzu City
-More spouse and children interaction
-Farmhands
-More quests
-Tractor (this is available as a mod)

World of Warcraft

Basically revamp everything from late WoTLK to present day. I would also expand BC to equal classic in terms of content updates. In fact I would be fine if every Expansion was like that.

The Witcher 3. A big expansion that just adds fully fledged Witcher contracts. Like one hundred of them scattered throughout the main games maps and DLC maps with some big money contracts thrown in for end game and a score or so more big narrative interlocking side quests here and there with some that are really high level so you have to return to them near or after end game and another sword and armour quest to go with them. I know that game us pretty big as is, esspecially with the DLC but the main pull here would be to have the choice to do new side content and be able to skip more of the content one would not want to redo or is to fresh in the memory.

Of course there are many little things I would add to the game now as it ages but this is the one thing I would want, I'm not sure I'd want a story expansion after B&W unless it's a Ciri expansion that follows after what now is supposed to be the true ending.

Chrono Trigger - Make it longer. Its a short game by today's standard (and also by my personal standards) and while I understand a lot of people like that, I personally think extending the story more and have more content would be something Id enjoy a lot.