What are some games you wouldn't play without mods?

The game that stands out to me is Fallout 4. The new dialogue system only hinted at what the protagonist was going to say with vague choices like "sarcastic" and that led me to reload saves frequently to either check out other options or because the protagonist came off as way too intense an railroaded me down a conversation route.

With Fallout 4 it's more of a quality of life thing but with Fallout 3/NV I feel like I need to mod the games for the sake of stability. I've lost a lot of progress because I was exploring the Capital Wasteland/Mojave without passing through an auto-save point so I rely pretty heavily on things like CASM.

Fallout 3, for a long time on Steam, used Games For Windows Live DRM which shutdown in 2013. This meant a majority of people needed some kind of games GFWL disabler to even launch the game. Some people used Tale of Two Wastelands (TTW) which essentially combine Fallout 3 and Fallout New Vegas into one game.

I am wondering what other games do people only play modded?

I feel like there must be a lot of niche games out there that have some kind of quality of life mod a sizeable chunk of players use.

Maybe it's an older game that relies heavily on mods or an open source engine recreation to run on modern systems.

I suppose another question would be which mods are essential in those situations