I have a few big saves, most of which are abandoned because at some point I get exhaused with all the drama I'm trying to remember and start anew.
"Strangers and Friends" is my very first Sims 4 save, created in June 2018 when I got the game at a steep discount and created three sims to test different aspects of the game. Two of the sims had a child, the other sim had a child with Liberty Lee, and the family blended into one which I followed for almost ten generations. I've loaded it up a few times since and don't play it, preferring to keep it intact as a memory of my first game.
"La Familia" is a multi-generational result of a sim-self which I used to test numerous mods. It was the first save to grow to the point that I could not keep track of what was going on, and started forgetting the stories I had.
"Pleasantview sans Gia" is my playthrough of someone else's save, "Pleasantview 25 Years Later". It got a little bizarre, with multiple zombie invasions, plus a witch fighting a corporate overlord for control of the neighborhood.
"Pleasants so Merrie" is still active. I started it to test a mod and continued with it. I started it with my version of the Pleasant family in the inter-game games (Daniel and Mary Sue are a young couple with twin children) and it grew into a legacy of sorts, in which I began referring to the Pleasants as the royal family and now they all have titles like "Prince Morgan", "Lady Sabrina", etc.
There are a few others I'm forgetting about, but I'm not on my gaming computer and can't look at them immediately.