I always wait for a game where you manage a remote Starbase and the main part is to put together Spaceships out of parts made by yourself or salvaged from fights. So you repair and build them out of a limited amount of parts and assign them to your pilots, give them patrols or mining missions etc.

An FPS where your NPC allies/companions don't routinely run in front of you while you're shooting

An RPG hat doesn't have unique items buried in a radiant/procedurally generated quest line

I want a new ski resort simulator game that also has the summer season.

No one has done a bug free version of the ski side in probably 2 decades at this point...

If Crusader Kings is ever combined with Mount & Blade, I'll never see daylight again.

A “legacy” game, where your contributions to the game continue even if you’re logged off, meted with an mmorpg

It could be anything, but my idea is something like cities:skylines. Interconnected cities or areas each with a mayor or admins that direct the goals of the area..

Then the 2nd aspect of the game is more like GTA, where people interact with the areas.

The areas could be like San Andreas, but then you could walk to the edge and it becomes more like a village from Warcraft. Or maybe an area is filled with ghosts and most of the goals in the area are delivering packages. Or maybe there’s an area like Sanctum 2, fallout, or any other idea. It would be up to the admins/mayors to figure out how to design it.

The game would fill in gaps in city creation for random encounters, etc. the in-game players actions would have some effect on the area itself.

I would expect the game to support itself through a combination of ads and subs. Companies could pay to have more control over what advertising exists in their area.